The enthalpy change for the sublimation of iodine, represented by I₂(s) → I₂(g), is 31 kJ/mol.
Explanation:The enthalpy change for the sublimation of iodine, represented by I₂(s) → I₂(g), can be determined by comparing the enthalpy changes of the two given reactions. Since the equation ½ H₂(g) + ½ I₂(g) → HI(g) has a lower enthalpy change (-5.0 kJ/mol) compared to the equation ½ H₂(g) + ½ I₂(s) → HI(g) (26 kJ/mol), it means that the phase change from solid iodine to gaseous iodine requires an additional amount of energy. Thus, the enthalpy change for the sublimation of iodine is the difference between the two reaction enthalpies, which is 31 kJ/mol.
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Your lab partner named this compound 3-methyl-4-n-propylhexane, but that is not correct.
What is the correct IUPAC name?
Answer: The correct IUPAC name of the alkane is 4-ethyl-3-methylheptane
Explanation:
The IUPAC nomenclature of alkanes are given as follows:
Select the longest possible carbon chain.For the number of carbon atom, we add prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'sept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10.A suffix '-ane' is added at the end of the name.If two of more similar alkyl groups are present, then the words 'di', 'tri' 'tetra' and so on are used to specify the number of times these alkyl groups appear in the chain.We are given:
An alkane having chemical name as 3-methyl-4-n-propylhexane. This will not be the correct name of the alkane because the longest possible carbon chain has 7 Carbon atoms, not 6 carbon atoms
The image of the given alkane is shown in the image below.
Hence, the correct IUPAC name of the alkane is 4-ethyl-3-methylheptane
The correct IUPAC name of the molecule is 2-cyclopropyl cyclohexane.
The IUPAC name of a molecule is also called the systematic name of the molecule. The IUPAC name of a molecule is given in such a way that the structure of the molecule can be drawn from its name.
The correct IUPAC name of the molecule is 2-cyclopropyl cyclohexane. The substituent in the molecule is the cyclopropyl moiety.
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If 0.060 faraday is passed through an electrolytic cell containing a solution of In3+ ions, the maximum number of moles of In that could be deposited at the cathode isA) 0.010 mole
B) 0.020 mole
C) 0.030 mole
D) 0.060 mole
E) 0.18 mole
Answer: option B. 0.020 mole
Explanation:Please see attachment for explanation
The maximum number of moles of In that could be deposited at the cathode is 0.02 mole.
The given parameters;
number of ions, n = +3 ionscharge passed through the electrolytes, Q = 0.06 FThe maximum number of moles of In that could be deposited at the cathode is calculated as follows;
3 ions = 3 F
3 F ----------------------- 1 mole of the ion
0.06 F ---------------------- ? mole of the ion
[tex]= \frac{0.06\ F \times 1}{3 \ F } \\\\= 0.02 \ mole[/tex]
Thus, the maximum number of moles of In that could be deposited at the cathode is 0.02 mole.
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The compound chromium(II) nitrate is a strong electrolyte. Write the reaction when solid chromium(II) nitrate is put into water:
Final answer:
Solid chromium(II) nitrate dissolves in water and dissociates into chromium ions and nitrate ions, indicating its strong electrolyte nature.
Explanation:
The question pertains to the dissolution of chromium(II) nitrate in water and its behavior as a strong electrolyte. When solid chromium(II) nitrate is placed in water, it will undergo the process of dissolution and dissociation since it is a strong electrolyte. This can be represented by the following chemical reaction:
Cr(NO3)2(s) → Cr2+(aq) + 2NO3−(aq)
Here, solid chromium(II) nitrate dissolves in water, producing chromium ions and nitrate ions, which are uniformly dispersed throughout the aqueous solution. The reaction showcases the strong electrolytic nature of chromium(II) nitrate, which allows it to completely dissociate in solution and conduct electricity.
The reaction is- [tex]\[ \text{Cr(NO}_3\text{)}_2(s) \rightarrow \text{Cr}^{2+}(aq) + 2\text{NO}_3^-(aq) \][/tex]
The reaction when solid chromium(II) nitrate [tex](Cr(NO\(_3\))\(_2\))[/tex] is dissolved in water can be represented by the following equation:
[tex]\[ \text{Cr(NO}_3\text{)}_2(s) \rightarrow \text{Cr}^{2+}(aq) + 2\text{NO}_3^-(aq) \][/tex]
When a strong electrolyte like chromium(II) nitrate dissolves in water, it dissociates completely into its constituent ions. Chromium(II) nitrate consists of the chromium(II) cation, [tex]Cr\(^{2+}\)[/tex], and the nitrate anion, [tex]NO\(_3\)\(^-\)[/tex]. The solid compound, represented by the (s) notation, separates into its ions in aqueous solution, as indicated by the (aq) notation.
The compound dissociates into one chromium(II) ion for every molecule of chromium(II) nitrate and two nitrate ions per molecule, as indicated by the stoichiometric coefficients in the balanced equation. The nitrate ion has a charge of -1, and since the chromium(II) ion has a charge of +2, two nitrate ions are required to balance the charge, resulting in a neutral compound. When dissolved, these ions are solvated by water molecules, but this aspect is not explicitly shown in the reaction equation.
"Synthesis gas" is a mixture of carbon monoxide and water vapor. At high temperature synthesis gas will form carbon dioxide and hydrogen, and in fact this reaction is one of the ways hydrogen is made industrially.
A chemical engineer studying this reaction fills a 200.mL flask at 12.°C with 1.3atm of carbon monoxide gas and 3.6atm of water vapor. He then raises the temperature considerably, and when the mixture has come to equilibrium determines that it contains 0.82atm of carbon monoxide gas, 3.12atm of water vapor and 0.48atm of carbon dioxide.
The engineer then adds another 0.43atm of carbon monoxide, and allows the mixture to come to equilibrium again. Calculate the pressure of hydrogen after equilibrium is reached the second time. Round your answer to 2 significant digits.
Answer:
0.56 atm
Explanation:
The equilibrium occurs when, in a reversible reaction, the velocity of the formation of the products is equal to the velocity of the formation of the reactants. In this scenario, the partial pressures and the concentration of the components remains constant.
The equilibrium can be characterized by the equilibrium constant, which can be calculated by the concentration (Kc), or by the partial pressure (Kp). In the expression of Kc, solids and pure liquids are not put, and in the expression of Kp, only gases are considered.
The constant is calculated by the product of the concentration, or pressure, of the products, elevated by their coefficients, divided by the product of the concentration, or pressure, of the reactants, elevated by their coefficients. Its value only changes with the temperature.
So, for the reaction given:
CO(g) + H₂O(g) ⇄ CO₂(g) + H₂(g)
1.3 atm 3.6 atm 0 0 Initial
-x -x +x +x Reacts (stoichiometry is 1:1:1:1)
1.3-x 3.6-x x x Equilibrium
At equilibrium:
pCO = 1.3 - x = 0.82
x = 1.3 - 0.82 = 0.48 atm
pH₂O = 3.12 atm
pCO₂ = 0.48 atm
pH₂ = 0.48 atm
Thus,
Kp = pCO₂*pH₂/(pCO*pH₂O)
Kp = 0.48*0.48/(0.82*3.12)
Kp = 0.090
When more carbon monoxide (CO) is added, the equilibrium will shift to the right, and more products will be formed, is order to reestablish the equilibrium (Le Chatelier's pricniple), so:
CO(g) + H₂O(g) ⇄ CO₂(g) + H₂(g)
0.82 atm 3.12 atm 0.48 atm 0.48 atm 1st equilibrium
1.25 3.12 0.48 0.48 After the CO addition
-x -x +x +x Reacts
1.25-x 3.12-x 0.48 +x 0.48+x New equilibrium
Because the temperature is the same, Kp = 0.090
0.090 = (0.48+x)*(0.48+x)/[(1.25-x)*(3.12-x)]
0.090 = (0.2304 + 0.96x + x²)/(3.9 - 4.37x + x²)
0.2304 + 0.96x + x² = 0.351 - 0.3933x + 0.09x²
0.91x² + 1.3533x - 0.1206 = 0
Solving this 2nd grade equation at a graphic calculator, for x > 0 and x < 1.25
x = 0.084 atm
pH₂ = 0.48 + 0.084
pH₂ = 0.56 atm
Assuming that all the H comes from HCl, how many grams of sodium hydrogen carbonate will totally neutralize the stomach acid?
The question is incomplete, here is the complete question:
Assuming that all the [tex]H^+[/tex] comes from HCl, how many grams of sodium hydrogen carbonate will totally neutralize the stomach acid? Volume = 500 mL pH= 2
Answer: The mass of sodium hydrogen carbonate needed to completely neutralize stomach acid is 0.42 grams
Explanation:
To calculate the hydrogen ion concentration of the solution, we use the equation:
[tex]pH=-\log[H^+][/tex]
We are given:
pH = 2
Putting values in above equation, we get:
[tex]2=-\log[H^+][/tex]
[tex][H^+]=10^{-2}M[/tex]
To calculate the number of moles for given molarity of solution, we use the equation:[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}[/tex]
Molarity of hydrogen ions = 0.01 M
Volume of solution = 500 mL = 0.5 L (Conversion factor: 1 L = 1000 mL)
Putting values in above equation, we get:
[tex]0.01M=\frac{\text{Moles of hydrogen ions}}{0.5L}\\\\\text{Moles of hydrogen ions}=(0.01mol/L\times 0.5L)=0.005mol[/tex]
The chemical equation for the reaction of HCl and sodium hydrogen carbonate follows:
[tex]HCl+NaHCO_3\rightarrow NaCl+H_2CO_3[/tex]
By Stoichiometry of the reaction:
1 mole of HCl reacts with 1 mole of sodium hydrogen carbonate
So, 0.005 moles of HCl will react with = [tex]\frac{1}{1}\times 0.005=0.005mol[/tex] of sodium hydrogen carbonate
To calculate the number of moles, we use the equation:[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Moles of sodium hydrogen carbonate = 0.005 moles
Molar mass of sodium hydrogen carbonate = 84 g/mol
Putting values in above equation, we get:
[tex]0.005mol=\frac{\text{Mass of sodium hydrogen carbonate}}{84g/mol}\\\\\text{Mass of sodium hydrogen carbonate}=(0.005mol\times 84g/mol)=0.42g[/tex]
Hence, the mass of sodium hydrogen carbonate needed to completely neutralize stomach acid is 0.42 grams
To determine the grams of sodium hydrogen carbonate needed to neutralize the stomach acid, we need to use the concept of stoichiometry.
Explanation:To determine the grams of sodium hydrogen carbonate needed to neutralize the stomach acid, we need to use the concept of stoichiometry. The balanced equation for the neutralization reaction is:
2HCl(aq) + NaHCO3(s) → NaCl(aq) + H2CO3(aq)
From the equation, we can see that 2 moles of HCl react with 1 mole of NaHCO3. Therefore, the number of moles of HCl can be calculated using the given volume and concentration, and then converted to moles of NaHCO3. Finally, the moles of NaHCO3 can be converted to grams using its molar mass.
Which of the following would require the largest volume of 0.100 M sodium hydroxide solution for neutralization?:
(A) 20.0 mL of 0.0500 M nitric acid
(B) 15.0 mL of 0.0500 M hydrobromic acid
(C) 5.0 mL of 0.0100 M sulfuric acid
(D) 10.0 mL of 0.00500 M phosphoric acid
Answer:10.0 mL of 0.00500 M phosphoric acid
Explanation:
If we look at the Ka values of the acids, we will realize that phosphoric acid has a Ka of 7.1 * 10-3. It is the only acid in the list having acid dissociation constant less than 1. This means that it does not ionize easily in solution and a very large volume of base must be added to ensure that it reacts completely. Acids with Ka >1 are generally regarded as strong acids. All the acids listed have Ka>1 except phosphoric acid.
20.0 mL of 0.0500 M nitric acid would require the largest volume of 0.100 M sodium hydroxide solution for neutralization based on calculations using molarity, volume, and the number of protons the acid can donate.
Explanation:An acid-base neutralization reaction takes place when an acid reacts with a base to produce a salt and water. The volume of base needed to neutralize an acid depends on the molarity and volume of the acid, as well as the number of protons (H+) each acid molecule can donate.
For each option, we can calculate the number of moles of H+ using the formula: moles = Molarity * Volume(L), and then using the 1:1 stoichiometry with sodium hydroxide (NaOH) for one-proton acids, or 1:2 stoichiometry for two-proton acids.
(A) 20.0 mL of 0.0500 M nitric acid (HNO₃): 0.0500 mol/L * 0.020 L = 0.00100 mol of H+(B) 15.0 mL of 0.0500 M hydrobromic acid (HBr): 0.0500 mol/L * 0.015 L = 0.00075 mol of H+(C) 5.0 mL of 0.0100 M sulfuric acid (H₂SO₄): 2(0.0100 mol/L * 0.005 L) = 0.00010 mol of H+(D) 10.0 mL of 0.00500 M phosphoric acid (H₃PO₄): 0.00500 mol/L * 0.010 L = 0.00005 mol of H+So, option (A) with 20.0 mL of 0.0500 M nitric acid would require the largest volume of 0.100 M sodium hydroxide solution for neutralization.
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Sulfuric acid is essential to dozens of important industries from steelmaking to plastics and pharmaceuticals. More sulfuric acid is made than any other industrial chemical, and world production exceeds per year. The first step in the synthesis of sulfuric acid is usually burning solid sulfur to make sulfur dioxide gas. Suppose an engineer studying this reaction introduces of solid sulfur and of oxygen gas at into an evacuated tank. The engineer believes for the reaction at this temperature. Calculate the mass of solid sulfur he expects to be consumed when the reaction reaches equilibrium. Round your answer to significant digits.
The question is incomplete, here is the complete question:
Sulfuric acid is essential to dozens of important industries from steel making to plastics and pharmaceuticals. More sulfuric acid is made than any other industrial chemical, and world production exceeds [tex]2.0\times 10^{11}[/tex] per year.
The first step in the synthesis of sulfuric acid is usually burning solid sulfur to make sulfur dioxide gas. Suppose an engineer studying this reaction introduces 4.4 kg of solid sulfur and 6.90 atm of oxygen gas at 950°C into an evacuated 50.0 L tank. The engineer believes [tex]K_p=0.71[/tex] for the reaction at this temperature.
Calculate the mass of solid sulfur he expects to be consumed when the reaction reaches equilibrium. Round your answer to 2 significant digits.
Answer: The mass of sulfur that is expected to be consumed is 0.046 kg
Explanation:
We are given:
Initial partial pressure of oxygen gas = 6.90 atm
The chemical equation for the formation of sulfur dioxide follows:
[tex]S(s)+O_2(g)\rightleftharpoons SO_2(g)[/tex]
Initial: 6.90
At eqllm: 6.90-x x
The expression of [tex]K_p[/tex] for above equation follows:
[tex]K_p=\frac{p_{SO_2}}{p_{O_2}}[/tex]
We are given:
[tex]K_p=0.71[/tex]
Putting values in above equation, we get:
[tex]0.71=\frac{x}{(6.9-x)}\\\\x=2.9[/tex]
So, equilibrium partial pressure of sulfur dioxide = x = 2.9 atm
To calculate the number of moles, we use the equation given by ideal gas, which follows:
PV = nRT
where,
P = pressure of sulfur dioxide gas = 2.9 atm
V = volume of the container = 50.0 L
n = number of moles of sulfur dioxide gas = ?
R = [tex]0.0821\text{ L. atm }mol^{-1}K^{-1}[/tex]
T = temperature of the container = [tex]950^oC=[950+273]K=1223K[/tex]
Putting values in above equation, we get:
[tex]2.9\times 50.0=n\times 0.0821\times 1223\\\\n=\frac{2.9\times 50.0}{0.0821\times 1223}=1.44mol[/tex]
Moles of sulfur dioxide = 1.44 moles
By Stoichiometry of the reaction:
1 mole of sulfur dioxide is produced from 1 mole of sulfur
So, 1.44 moles of sulfur dioxide will be produced from [tex]\frac{1}{1}\times 1.44=1.44mol[/tex] of sulfur
To calculate the mass of a substance, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Moles of sulfur = 1.44 moles
Molar mass of sulfur = 32 g/mol
Putting values in above equation, we get:
[tex]1.44mol=\frac{\text{Mass of sulfur}}{32g/mol}\\\\\text{Mass of sulfur}=(1.44mol\times 32g/mol)=46.08g=0.046kg[/tex]
Hence, the mass of sulfur that is expected to be consumed is 0.046 kg
Consider two solutions, solution A and solution B. [H+] in solution A is 500 times greater than that in solution B. what is the difference in the pH values of the two solutions?
Answer: The difference in the pH values of the two solutions is 2.7
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pH=-\log [H^+][/tex]
a) For solution A, let [tex][H^+][/tex] = [tex]0.0001\times 500M=0.05M[/tex]
Putting in the values:
[tex]pH=-\log[0.05][/tex]
[tex]pH=1.3[/tex]
b) For solution B, [tex][H^+][/tex] =[tex]0.0001M[/tex]
Putting in the values:
[tex]pH=-\log[0.0001][/tex]
[tex]pH=4[/tex]
Thus the difference in pH will be (4-1.3)= 2.7.
The difference in the pH values of the two solutions is 2.7
Let the [H+] of solution B be 0.0001 M
Thus,
The [H+] of solution A = 0.0001 × 500 = 0.05 M
Next, we shall determine the pH of each solutionFor solution A:
Hydrogen ion concentration [H+] = 0.0001 M
pH =?
pH = –Log [H+]
pH = –Log 0.0001
pH = 1.3For solution B:
Hydrogen ion concentration [H+] = 0.05 M
pH =?
pH = –Log [H+]
pH = –Log 0.05
pH = 4Finally, we shall determine the difference in the pH values of the two solutionspH of solution A = 1.3
pH of solution B = 4
Difference =?Difference = 4 – 1.3
Difference = 2.7Therefore, the difference in the pH values of the two solutions is 2.7
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Which type of fermentation produces CO2 bubbles in baking?
a)Homolactic fermentation
b)Oxidative phosphorylation
c)Alcoholic fermentation
d)Butanediol fermentation
Alcoholic fermentation fermentation produces CO2 bubbles in baking.
Explanation:
The other name given for the Alcoholic Fermentation is Ethanol fermentation. In this process of fermentation, ethanol and carbon dioxide are the resultant by-products. These are formed by the conversion of fructose,sucrose and glucose to cellular energy. This type of fermentation do not require oxygen for the process to take place. Hence, these are known to be an anaerobic process
This type of fermentation has its application like ethanol fuel production, cooking of bread, etc. A dough rises of the Ethanol fermentation. this is because, the sugars that are present in a dough are absorbed by yeast . this produces ethanol and carbon dioxide. During baking process,bubbles are formed by this carbon dioxide.
A closed vessel having a volume of 1 liter holds 2.5 × 1022 molecules of carbon dioxide gas. Determine the mass of CO2 present, in kg and the number of moles, in kmol. Determine the specific volume of the CO2, in m3/kg, and the molar specific volume, in m3/kmol.
Answer:
mass = 1.8x10⁻³ kg; number of moles = 4.1x10⁻⁵ kmol; specific volume = 0.55 m³/kg; molar specific volume = 24.4 m³/kmol
Explanation:
By the Avogadro's number, 1 mol of the matter has 6.02x10²³ molecules, thus, the number of moles (n) is the number of molecules presented divided by Avogadro's number:
n = 2.5x10²²/6.02x10²³
n = 0.041 mol
n = 4.1x10⁻⁵ kmol
The molar mass of CO₂ is 44 g/mol (12 g/mol of C + 2*16g/mol of O), and the mass is the number of moles multiplied by the molar mass:
m = 0.041 mol * 44 g/mol
m = 1.804 g
m = 1.8x10⁻³ kg
The specific volume (v) is the volume (1L = 0.001 m³) divided by the mass, and it represents how much volume is presented in each part of the mass:
v = 0.001/1.8x10⁻³
v = 0.55 m³/kg
The molar specific volume (nv) is the volume divided by the number of moles, and it represents how much volume is presented in each part of the mol:
nv = 0.001/4.1x10⁻⁵
nv = 24.4 m³/kmol
The study of the chemicals and the bonds is called chemistry.
The correct answer is 24.4
What are moles?The mole is the base unit of the amount of substance in the International System of Units. It is defined as exactly [tex]6.02214076*10^{23 [/tex] elementary entities, which may be atoms, molecules, ions, or electrons.All the data is given is as follows:-
Mass = 1.8x10⁻³Number of moles = 4.1x10⁻⁵Specific volume= 0.55 Molar specific volume = 24.4By the Avogadro's number, 1 mole of the matter has 6.02x10²³ molecules, thus, the number of moles (n) is the number of molecules presented divided by Avogadro's number:
n = [tex]\frac{2.5*10^{22}}{{6.02*10^{23}}} [/tex]
n = 0.041 mol
n = [tex]4.1*106^{-5[/tex] kmol
The molar mass of CO₂ is 44 g/mol ([tex]12 g/mol of C + 2*16g/mol of O[/tex]), and the mass is the number of moles multiplied by the molar mass:
m = 0.041 mol * 44 g/mol
m = 1.804 g
m = [tex]1.8x10^{-3} kg[/tex]
The specific volume (v) is the volume (1L = 0.001 m³) divided by the mass, and it represents how much volume is presented in each part of the mass:
v = [tex]\frac{0.001}{1.8*10^{-3}}[/tex]
v = 0.55 m³/kg
The molar specific volume (nv) is the volume divided by the number of moles, and it represents how much volume is presented in each part of the mol:
nv = 0.001/4.1x10⁻⁵
nv = 24.4 m³/kmol
Hence, the correct answer is 24.4.
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A student wants to make a 0.150 M aqueous solution of silver nitrate, AgNO3, and has a bottle containing 11.27 g of silver nitrate. What should be the final volume of the solution
Answer:
V = 0.44 L
Explanation:
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = 11.27 g
m ( for AgNO₃ ) = 169.87 g/mol
Hence , the moles can be calculated as -
n = w / m
n = 11.27 g / 169.87 g/mol
n = 0.066 mol
Molarity -
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
From the question ,
M = 0.150 M
n = 0.066 mol ( calculated above )
The final volume of the solution can be calculated by using the above equation ,
M = n / V
0.150 M = 0.066 mol / V
V = 0.44 L
The correct final volume of the solution is 1.00 L.
To find the final volume of the solution, we need to use the formula for molarity (M), which is given by:
[tex]\[ M = \frac{\text{moles of solute}}{\text{liters of solution}} \][/tex]
First, we calculate the moles of silver nitrate (AgNO3) using the given mass and the molar mass of AgNO3. The molar mass of AgNO3 is 169.87 g/mol, which is the sum of the atomic masses of silver (Ag, 107.87 g/mol), nitrogen (N, 14.01 g/mol), and three times the atomic mass of oxygen (O, 16.00 g/mol):
[tex]\[ \text{moles of AgNO3} = \frac{\text{mass of AgNO3}}{\text{molar mass of AgNO3}} \][/tex]
[tex]\[ \text{moles of AgNO3} = \frac{11.27 \text{ g}}{169.87 \text{ g/mol}} \][/tex]
[tex]\[ \text{moles of AgNO3} = 0.0664 \text{ mol} \][/tex]
Now, we want to make a 0.150 M solution, so we set up the equation for molarity with the moles of AgNO3 we have and solve for the volume (V):
[tex]\[ M = \frac{\text{moles of solute}}{V} \][/tex]
[tex]\[ 0.150 \text{ M} = \frac{0.0664 \text{ mol}}{V} \][/tex]
[tex]\[ V = \frac{0.0664 \text{ mol}}{0.150 \text{ M}} \][/tex]
[tex]\[ V = 0.4427 \text{ L} \][/tex]
However, we want the final volume to be in liters and to have a reasonable number of significant figures. Since the mass of AgNO3 is given to four decimal places, we can have four significant figures in our volume. Thus, we round the volume to 0.4427 L, which is equivalent to 442.7 mL.
To make the solution up to 1 L, as is common practice in the lab, we would transfer the 442.7 mL of the AgNO3 solution to a 1 L volumetric flask and add distilled water to the mark on the neck of the flask, which indicates the volume is exactly 1 L. This ensures that the final concentration of the solution is 0.150 M.
Therefore, the final volume of the solution should be 1.00 L to achieve the desired molarity of 0.150 M.
Can you help with part B
Part A
Acetylene, C2H2, can be converted to ethane, C2H6, by a process known as hydrogenation. The reaction is
C2H2(g)+2H2(g)⇌C2H6(g)
Given the following data at standard conditions (all pressures equal to 1 atm and the common reference temperature 298 K), what is the value of Kp for this reaction?
Substance ΔG∘f
(kJ/mol)
C2H2(g) 209.2
H2(g) 0
C2H6(g) −32.89
Express your answer using two significant figures.
Kp =
2.7×1042
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Correct
Based on the magnitude of K, we know that this reaction has practically gone to completion at equilibrium.
Standard versus Nonstandard Conditions
In Part A, we saw that ΔG∘=−242.1 kJ for the hydrogenation of acetylene under standard conditions (all pressures equal to 1 atm and the common reference temperature 298 K). In Part B, you will determine the ΔG for the reaction under a given set of nonstandard conditions.
Answer:
[tex]\delta G= -261.2kg[/tex] for the reaction under a given set of nonstandard conditions.
Explanation:
[tex]C_{2}H_6(g) + 2H_2(g)\rightleftharpoons C_2H_6(g)[/tex]
[tex]Q_p = \frac{P_c_2H_6}{P_c_2H_2\timesP_H_2}[/tex]
= [tex]\frac{3.25\times10^-2}{4.25\times4.15}[/tex]
[tex]Q_p[/tex] = [tex]4.44 \times 10^-4[/tex]
[tex]\delta G =\delta G^0 + RTlnQ_P[/tex]
= [tex]-242.1+8.314\times10^-3\times298\timesln(4.44\times10^-4)[/tex]
= [tex]\delta G= -261.2kg[/tex]
So, [tex]\delta G= -261.2kg[/tex]
his is the chemical formula for chromium(III) nitrate: . Calculate the mass percent of oxygen in chromium(III) nitrate. Round your answer to the nearest percentage.
Mass percent is a technique of expressing or defining a concentration or a component in a combination. The mass percent of oxygen in chromium(III) nitrate is approximately 60.5%.
To calculate the mass percent of oxygen in chromium(III) nitrate (Cr(NO₃)₃), we need to determine the molar mass of the compound and the molar mass of the oxygen atoms in the compound.
The molar mass of Cr(NO₃)₃ can be calculated by adding the molar masses of the individual atoms in the compound:
Molar mass of Cr(NO₃)₃ = (1 x molar mass of Cr) + (3 x molar mass of N) + (9 x molar mass of O)
Molar mass of Cr(NO₃)₃ = (1 x 52.00 g/mol) + (3 x 14.01 g/mol) + (9 x 16.00 g/mol)
Molar mass of Cr(NO₃)₃ = 238.03 g/mol
The molar mass of the oxygen atoms in Cr(NO₃)₃ can be calculated by multiplying the molar mass of oxygen by the number of oxygen atoms in the compound:
Molar mass of O in Cr(NO₃)₃ = 16.00 g/mol x 9
Molar mass of O in Cr(NO₃)₃ = 144.00 g/mol
To calculate the mass percent of oxygen in Cr(NO₃)₃, we can use the formula:
The mass percent of oxygen = (mass of O in compound / molar mass of compound) x 100%
Mass percent of oxygen = (144.00 g/mol / 238.03 g/mol) x 100%
The mass percent of oxygen ≈ 60.5%
Therefore, the mass percent of oxygen in chromium(III) nitrate is approximately 60.5%.
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To calculate the mass percent of oxygen in chromium(III) nitrate, we need to determine the molar mass of the compound and the molar mass of oxygen. The molar mass of Cr(NO3)3 is calculated to be 291.97 g/mol. The mass percent of oxygen in chromium(III) nitrate is approximately 55.24%.
Explanation:To calculate the mass percent of oxygen in chromium(III) nitrate, we need to determine the molar mass of the compound and the molar mass of oxygen. The formula for chromium(III) nitrate is Cr(NO3)3.
The molar mass of Cr(NO3)3 can be calculated as follows:
Molar mass of Cr = 51.996 g/mol
Molar mass of N = 14.007 g/mol
Molar mass of O = 15.999 g/mol
Molar mass of Cr(NO3)3 = (51.996 g/mol) + 3*(14.007 g/mol) + 9*(15.999 g/mol) = 291.97 g/mol
The molar mass of oxygen is 15.999 g/mol. The mass percent of oxygen in chromium(III) nitrate can be calculated as:
Mass percent of O = (mass of O / molar mass of Cr(NO3)3) * 100%
Mass percent of O = (9*(15.999 g/mol) / 291.97 g/mol) * 100% = 55.24%
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What mass (in g) of KIO3 is needed to prepare 50.0 mL of 0.20 M KIO3? b) What volume (in mL) of 0.15 m H2SO4 is needed to prepare 50.0 mL of 0.080 M H2SO4?
Final answer:
To prepare a 0.20 M KIO3 solution, 2.14 g of KIO3 is required for 50.0 mL. For the 0.080 M H2SO4 solution, 26.7 mL of 0.15 M H2SO4 is needed to dilute to 50.0 mL.
Explanation:
To calculate the mass (in g) of KIO3 needed to prepare 50.0 mL of a 0.20 M solution, use the formula:
mass = molarity × volume × molar mass
We begin by calculating the moles of KIO3 needed:
Moles of KIO3 = Molarity × Volume (in L)
= 0.20 mol/L × 0.0500 L = 0.010 moles of KIO3
The molar mass of KIO3 is K (39.10 g/mol) + I (126.90 g/mol) + 3×O (3× 16.00 g/mol) = 214.00 g/mol.
Now calculate the mass:
Mass of KIO3 = Moles × Molar Mass
= 0.010 moles × 214.00 g/mol = 2.14 g
For the second part, to find the volume (in mL) of 0.15 M H2SO4 needed to prepare 50.0 mL of a 0.080 M solution, we use the dilution formula:
M1V1 = M2V2, where M is molarity and V is volume.
The initial molarity (M1) is 0.15 M, the final molarity (M2) is 0.080 M, and the final volume (V2) is 50.0 mL. We solve for V1:
V1 = (M2V2) / M1
= (0.080 M × 50.0 mL) / 0.15 M = 26.7 mL
Accordingly, you would need 26.7 mL of the 0.15 M H2SO4.
What are the melting points and safety concerns associated with the use of copper and sulfur?
Answer:
The answer is explained below.
Explanation:
The melting point is a physical property of a substance and is the temperature at which the material changes from a solid to a liquid state at atmospheric pressure.
Melting point of copper
The melting point of copper (Cu) with atomic number 29 is 1,085 °C
Safety concerns associated with the use of copper
Excess copper inhibits plants growth.Copper can affect the activity in soils, as it negatively influences the activity of microorganisms and earthworms.Exposure of the body to copper can irritate the skin and eyes.Copper may negatively affect the liver and kidneys.Copper is also known to cause vomiting, headaches and dizziness when exposed for long.Melting point of sulfur
The melting point of sulfur (S) with atomic number 16 is 115.2 °C
Safety concerns associated with the use of sulfur
Long term exposure Increases susceptibility to respiratory infections.Ingesting too much sulfur may cause diarrhea and blurred vision.Chronic exposure can affect the sense of smelling. If animals eat too much sulfur, it may affect the stomach and intestines, and cause neurological disorders.Prolonged inhalation exposure may cause severe breathing difficulties.Thermal burn from molten sulfur when in contact with the skin, can cause dryness, mild irritation.Sulfur in excess can cause brain cell death.What volume of propane (C3H8) is required to produce 165 liters of water according to the following reaction? (All gases are at the same temperature and pressure.) propane (C3H8) (g) + oxygen(g)carbon dioxide (g) + water(g)
Answer:
We need 41.2 L of propane
Explanation:
Step 1: Data given
volume of H2O = 165 L
Step 2: The balanced equation
C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g)
Step 3: Calculate moles of H2O
1 mol = 22.4 L
165 L = 7.37 moles
Step 4: Calculate moles of propane
For 1 mol C3H8 we need 5 moles O2 to produce 3 moles CO2 and 4 moles H2O
For 7.37 moles H2O we need 7.37/4 = 1.84 moles propane
Step 5: Calculate volume of propane
1 mol = 22.4 L
1.84 moles = 41.2 L
We need 41.2 L of propane
In which of the following pure substances would hydrogen bonding be expected?
a. cyclobutane
b. propanoic acid
c. acetone
d. All of the Above
Hydrogen bonding typically involves a hydrogen atom attached to a highly electronegative atom. In the given choices, only b- propanoic acid, which contains a hydrogen bound to an oxygen atom in a carboxylic acid group, meets this criterion.
Explanation:In considering which of the following pure substances would hydrogen bonding be expected, you need to examine the molecular structure. Hydrogen bonding typically occurs when a hydrogen atom attached to a highly electronegative atom like nitrogen, oxygen or fluorine is in the vicinity of another electronegative atom.
cyclobutane does not have any such atoms, so it would not be expected to exhibit hydrogen bonding. Propanoic acid, on the other hand, contains a carboxylic acid group (COOH) which consists of a hydrogen atom bound to an oxygen atom, so it should display hydrogen bonding. Acetone, however, while it does contain oxygen, doesn't have hydrogen directly bonded to the oxygen, reducing its ability to form hydrogen bonds.
Therefore, out of cyclobutane, propanoic acid, and acetone, only propanoic acid would be expected to exhibit hydrogen bonding.
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The Thompson analogy titled "The Carpet-Seed Children Analogy" attempts to deal with the issue of failed ____________________(A) fertilization(B) intercourse(C) conception(D) contraception
The Thompson analogy of the carpet seed children analogy has been based on the faulty contraceptive analogy for abortion. Thus, option D is correct.
Thompson's analogy of "The Carpet-Seed Children Analogy" has dealt with the failed pregnancy issues. Reproduction has been the process of the fusion of the gametes and the development of the zygote into the child.
The reproduction takes place inside the uterus of the female and has been termed pregnancy. There have been several complications with the pregnancy that leads to the abortion of the child.
The Thompson analogy of the carpet seed children analogy has been based on the faulty contraceptive analogy for abortion. Thus, option D is correct.
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An air stream enters a variable area channel at a velocity of 30 m/s with a pressure of 120 kPa and a temperature of 10°C. At a certain point in the channel, the velocity is found to be 250 m/s. Using Bernoulli’s equation (i.e., p + rhoV2 /2 = constant), which assumes incompressible flow, find the pressure at this point. In this calculation, use the density evaluated at the inlet conditions. If the temperature of the air is assumed to remain constant, evaluate the air density at the point in the flow where the velocity is 250 m/s. Compare this density with the density at the inlet to the channel. Based on this comparison, do you think that the use of Bernoulli’s equation is justified
Answer:
P₂= 74 kPa under constant density and ρ₂ = 1.06 kg/m³ (-38.6% of error compared with incompresible assumption) . Thus Bernoulli’s equation should not be applied
Explanation:
Assuming ideal gas behaviour of air , then
P*V= n*R*T = m / M * R *T
since
ρ= m/V = P*M /( R *T)
where
n= moles , V= volume , m= mass
ρ= density
P= pressure = 120 kPa= 120000 Pa
M= molecular weight of air = 0.21*32+0.79*28= 28.24 gr/mol = 0.02824 kg/mol
T= absolute temperature = 10°C + 273 = 283 K
R= ideal gas constant = 8.314 J/mol K
solving for ρ
ρ= P*M /( R *T) = 120000 Pa*0.02824 kg/mol/(8.314 J/mol K*283 K) = 1.47 kg/m³
then from Bernoulli's equation
P₁ + ρ*v₁²/2 = P₂ + ρ*v₂²/2
where 1 denotes inlet and 2 denotes other point , p = pressure and v= velocity . Then solving for p₂
P₁ + ρ*v₁²/2 = P₂ +ρ*P₂²/2
P₂= P₁ +ρ*v₁²/2 - ρ*v₂²/2 = P₁ +ρ/2*(v₁² - v₂²)
replacing values
P₂= P₁ +ρ/2*(v₁² - v₂²) = 120000 Pa + 1.47 kg/m³/2*[(30 m/s)²-(250 m/s)²] = 74724 Pa = 74 kPa
P₂= 74 kPa
then if the temperature remains constant
ρ₁= P₁*M /( R *T) and ρ₂= P₂*M /( R *T)
dividing both equations
ρ₂/ρ₁ = P₂/ P₁
ρ₂ = (P₂/ P₁)*ρ₁
then from Bernoulli's equation
P₁ + ρ₁*v₁²/2 = P₂ + ρ₂*v₂²/2
P₂ = P₁ + ρ₁*v₁²/2 - ρ₂*v₂²/2
therefore
ρ₂ = (P₂/ P₁)*ρ₁ = (P₁ + ρ₁*v₁²/2 - ρ₂*v₂²/2 ) /P₁ *ρ₁
P₁ * ρ₂ = P₁ *ρ₁ + ρ₁²*v₁²/2 - ρ₂*ρ₁ * v₂²/2
P₁ * ρ₂ + ρ₂*ρ₁ * v₂²/2 = P₁ *ρ₁ + ρ₁²*v₁²/2
ρ₂* (P₁ + ρ₁ * v₂²/2) = P₁ *ρ₁ + ρ₁²*v₁²/2
ρ₂ = (P₁ *ρ₁ + ρ₁²*v₁²/2)/(P₁ + ρ₁ * v₂²/2) = (P₁ + ρ₁*v₁²/2)/(P₁/ρ₁ + v₂²/2)
replacing values
ρ₂ = ( 120000 Pa + 1.47 kg/m³/2*(30 m/s)²)/(120000 Pa/1.47 kg/m³+1/2*(250 m/s)²)
ρ₂ = 1.06 kg/m³
the error of assuming constant ρ would be
e = (ρ₂ - ρ)/ρ₂= 1- ρ/ρ₂= 1- 1.47 kg/m³/1.06 kg/m³ = -0.386 (-38.6%)
thus Bernoulli’s equation should not be applied
Which of the following pieces of glassware would be best to choose for the following tasks?
For each task, select either the volumetric flask, Erlenmeyer flask, beaker, volumetric pipet, or graduate cylinder and explain why it would be the best choice.
a. Accurately deliver 15.00 mL of solution
b. Heat a reaction mixture on a hot plate
c. Accurately make a diluted solution to four significant figures
d. Approximately deliver 15 mL of solution
a) For accurately deliver 15.00 mL of solution- volumetric flask should be used.
b)For heating a reaction mixture on a hot plate- beaker should be used.
c)For accurately make a diluted solution to four significant figures- volumetric pipet should be used.
d) For approximately deliver 15 mL of solution- graduate cylinder should be used.
A graduated cylinder is a common piece of laboratory equipment used to measure the volume of a liquid.A volumetric flask is a type of laboratory flask, calibrated to contain a precise volume at a certain temperature.A beaker is generally a cylindrical container with a flat bottom.A volumetric pipette allows extremely accurate measurement (to four significant figures) of the volume of a solutionLearn more:
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Final answer:
For accurately delivering 15.00 mL, use a volumetric pipet; for heating, an Erlenmeyer flask; for making a precise diluted solution, a volumetric flask; and for approximate delivery of 15 mL, a graduated cylinder.
Explanation:
To choose the appropriate piece of glassware for each task, we must consider the accuracy and precision required, as well as the suitable functionality of each option.
d. Approximately deliver 15 mL of solution: A graduated cylinder can be used for this purpose as it is designed to deliver variable volumes of liquid with reasonable accuracy but does not require the high precision of a volumetric pipet or flask.
Rank the following molecules using numbers 1 - 4 in order of increasing boiling points (i.e. you would input 1 for the molecule with the lowest boiling point.)
A. decane
B. 3,3,4,4-tetramethylhexane
C. 2,2-dimethylpropane
D. dodecane
Answer:
B<C<A<D
Explanation:
The boiling point of alkanes increases with increasing chain length. Heavily branched alkanes usually show lower boiling points because of smaller dispersion forces. The longer the hydrocarbon chain, the higher the expected boiling point due to greater dispersion forces. This accounts for the order of increasing boiling points stated. Dodecane, a long chain alkanes us expected to have the highest boiling point, filled by decane then the di substituted before the tetra substituted alkanes which has the lowest boiling point.
The correct ranking of the molecules from the lowest to the highest boiling point is:
1. 2,2-dimethylpropane (C)
2. decane (A)
3. 3,3,4,4-tetramethylhexane (B)
4. dodecane (D)
Boiling points of molecules are influenced by several factors, with molecular weight and intermolecular forces being the most significant. Generally, as the molecular weight increases, the boiling point also increases due to stronger London dispersion forces. Additionally, branching in alkanes decreases the surface area available for intermolecular interactions, leading to lower boiling points compared to straight-chain alkanes of similar molecular weight.
Let's analyze each molecule:
A. Decane (C10H22) is a straight-chain alkane with 10 carbon atoms. It has a higher molecular weight than the other molecules except for dodecane, which means it will have relatively strong London dispersion forces.
B. 3,3,4,4-Tetramethylhexane (C10H22) is an isomer of decane with the same molecular formula but with more branching. The branching reduces the surface area for intermolecular interactions, which typically results in a lower boiling point compared to straight-chain decane.
C. 2,2-Dimethylpropane (C5H12), also known as neopentane, is highly branched and has the lowest molecular weight among the given molecules. Its highly branched structure minimizes the surface area for intermolecular interactions, leading to the weakest London dispersion forces and, consequently, the lowest boiling point.
D. Dodecane (C12H26) has the highest molecular weight among the given molecules, with 12 carbon atoms in a straight chain. It will have the strongest London dispersion forces and, therefore, the highest boiling point.
Based on these considerations, the molecules can be ranked in order of increasing boiling points as follows:
1. 2,2-Dimethylpropane (C) - Lowest molecular weight and highest degree of branching.
2. Decane (A) - Higher molecular weight than 2,2-dimethylpropane but less than dodecane, and less branching than 3,3,4,4-tetramethylhexane.
3. 3,3,4,4-Tetramethylhexane (B) - Same molecular weight as decane but more branching, which slightly lowers its boiling point compared to decane.
4. Dodecane (D) - Highest molecular weight and a straight chain, resulting in the strongest intermolecular forces and the highest boiling point."
For the reaction below, calculate the number of moles of NH3 that would be formed when 5.5 moles of N2H4 reacts completely:3N2H4 --> 4NH3 + N2
Answer:
7.33 moles of NH₃ are produced in the reaction.
Explanation:
The reaction is this:
3 N₂H₄ → 4NH₃ + N₂
Ratio is 3:4
So 3 moles of N₂H₄ were needed to produce 4 moles of ammonia
5.5 moles of N₂H₄ would produce (5.5 . 4 ) / 3 = 7.33 moles of NH₃
By titration, it is found that 65.5 mL of 0.117 M NaOH ( aq ) is needed to neutralize 25.0 mL of HCl ( aq ) . Calculate the concentration of the HCl solution.
Answer:
0.30 M
Explanation:
In case of titration , the following formula can be used -
M₁V₁ = M₂V₂
where ,
M₁ = concentration of acid ,
V₁ = volume of acid ,
M₂ = concentration of base,
V₂ = volume of base .
from , the question ,
M₁ = ? M
V₁ = 25.0 mL
M₂ = 0.117 M
V₂ = 65.5 mL
Using the above formula , the molarity of acid , can be calculated as ,
M₁V₁ = M₂V₂
Putting the respective values -
M₁ * 25.0mL = 0.117 M * 65.5 mL
M₁ = 0.30 M
Consider the Williamson ether synthesis between 2-naphthol and 1-bromobutane in strong base. A reaction was performed in which 0.51 g of 2-naphthol was reacted with a slight excess of 1-bromobutane to make 0.29 g of 2-butoxynaphthalene. Calculate the theoretical yield and percent yield for this reaction.Figure:Chemical bonds
Answer:
0.70 g
41 %
Explanation:
We can write the Williamson ether synthesis in a general form as:
R-OH + R´-Br ⇒ R-O-R´
where R-OH is an alcohol and R´-Br is an alkyl bromide.
We then see that the reaction occurs in a 1:1 mole ratio to produce 1 mol product.
Therefore what we need to calculate the theoretical yield and percent yield is to compute the theoretical number of moles of 2-butoxynaphthalene produced from 0.51 g 2-naphthol, and from there we can calculate the percent yield.
molar mass 2-naphthol = 144.17 g/mol
moles 2-naphthol = 0.51 g / 144.17 g/mol = 0.0035 mol 2-naphthol
The number of moles of produced:
= 0.0035 mol 2-naphthol x ( 1 mol 2-butoxynaphthalene /mol 2-naphthol )
= 0.0035 mol 2-butoxynaphthalene
The theoretical yield will be
= 0.0035 mol 2-butoxynaphthalene x molar mass 2-butoxynaphthalene
= 0.0035 mol x 200.28 g/ mol = 0.70 g
percent yield= ( 0.29 g / 0.70 ) g x 100 = 41 %
The theoretical yield of 2-butoxynaphthalene in the reaction between 2-naphthol and 1-bromobutane can be calculated by comparing the number of moles of the limiting reagent to the number of moles of the product. The percent yield of the reaction can be determined by dividing the actual yield by the theoretical yield and multiplying by 100.
Explanation:In the Williamson ether synthesis reaction between 2-naphthol and 1-bromobutane in a strong base, 0.51 g of 2-naphthol reacted with a slight excess of 1-bromobutane to produce 0.29 g of 2-butoxynaphthalene. To calculate the theoretical yield, we need to compare the number of moles of the limiting reagent, which is 2-naphthol, to the number of moles of the product. The molar masses of 2-naphthol and 2-butoxynaphthalene are calculated and the theoretical yield is determined to be 0.348 g.
The percent yield of the reaction can be calculated by dividing the actual yield (0.29 g) by the theoretical yield (0.348 g) and multiplying by 100. The percent yield for this reaction is approximately 83.3%.
C6H6NCl On the basis of the molecular formula, 1H NMR data, and IR data provided, propose a consistent structure.
H`NMR data: δ 300 (s, 2H), 6.57 (d, 2H), 7.05 (d, 2H)
IR data: 3400 (broad), 3250 (broad), 1590, 820 cm^(-1).
Draw your proposed structure below.
Answer:
Please refer to the attachment below.
Explanation:
Please refer to the attachment below for explanation.
Final answer:
Based on the IR and NMR data, and the molecular formula C6H6NCl, the likely structure is para-chloroaniline, which includes a benzene ring substituted with an amine group (NH2) and a chlorine atom (Cl).
Explanation:
The question involves determining the structure of a compound with the molecular formula C6H6NCl using 1H NMR and IR data. The 1H NMR data features signals at δ 300 (s, 2H), 6.57 (d, 2H), and 7.05 (d, 2H). The IR data presents broad bands at 3400 cm⁻¹ and 3250 cm⁻¹, which suggest the presence of N-H bonds, indicating an amine or amide functional group. The bands at 1590 cm⁻¹ and 820 cm⁻¹ can be indicative of an aromatic ring and substituted benzene, respectively.
Considering the molecular formula and the spectroscopy data given, a probable structure is a chloroaniline, where a benzene ring is substituted with an amine (NH2) group and a chlorine atom (Cl). The two doublets in the 1H NMR spectrum at 6.57 and 7.05 ppm suggest a para-substituted benzene ring, with each set of doublets representing the protons on either side of the substituted positions. The chemical shift at δ 300 ppm is not standard and is assumed to be a typo. Typically, for aromatic protons, shifts are in the range of 6-8 ppm. Thus, the illustrated doublets fit the pattern of para-substituted benzene.
Caffeine (C_8H_10N_4O_2) is a weak base with a K_b value of 4 times 10^-4. The pH of a 0.01 M solution of caffeine is in the range of: a. 2-3 b. 5-6 c. 7-8 d. 9-10 e. 11-12
Answer:
The pH of the solution lies from 11 to 12.Hence, option e is correct.
Explanation:
The value of [tex]K_b[/tex] for caffine = [tex]4\times 10^{-4}[/tex]
[tex]CafOH(aq)\rightleftharpoons Caf(aq)+OH^-(aq)[/tex]
Initial
0 0.01 M 0
AT equilibrium:
x (0.01 -x)M x
[tex]K_b=\frac{x(0.01-x)}{(x)}[/tex]
[tex]4\times 10^{-4}=\frac{x(0.01-x)}{(x)}[/tex]
Solving for x:
x = 0.0096 M
The pOH of the solution is given by :
[tex]pOH=-\log[OH^-}[/tex]
[tex]pOH=-\log[x][/tex]
[tex]pOH=-\log[0.0096][/tex]
pOH = 2.02
pH= 14 - pOH = 14 - 2.02 = 11.98
The pH of the solution lies from 11 to 12.
pH is the measurement of the acidity and alkaline level of a solution. It indicates the levels of hydrogen ions present in the solution.
pH can be calculated as :
pH = - log [H₃O+]
The correct answer is :
Option D. 11-12
To calculate the pH of a solution we need to know the concentration of hydronium ion in moles per litre.
Given,
The value of Kb of caffeine= 4 × 10⁻⁴
[tex]\text {Caf OH}\; \text{(aq)} \rightleftharpoons \text{Caf (aq)} & \; + \text{OH}^{-} \text{(aq)}[/tex]
Initially:
0 0.01 M 0
At the equilibrium:
Y (0.01- Y)M Y
[tex]\text{K}_{\text{b}} & = \frac{\text{Y}(0.01 - \text{Y})}{\text{Y}}[/tex]
[tex]4 \times 10^{-4} = \frac{\text{Y}(0.01 - \text{Y})}{\text{Y}}[/tex]
Solving for Y:
Y = 0.0096 M
The pOH of the solution can be determined by:
[tex]\text{pOH} & = \text{- log}\; (\text{OH}^{-} )[/tex]
[tex]\text{pOH} & = \text{- log}\; (\text{Y} )[/tex]
[tex]\text{pOH} & = \text{- log}\; (0.0096)[/tex]
pOH = 2.02
pH = 14- pOH
= 14-2.02
= 11.98
Therefore, the pH of the solution ranges between 11 - 12.
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"How would you make 100 mL of a carbonic acid buffer at 0.5 M and pH = 6.0 using 1.0 M NaHCO3 and either 1.0 M NaOH or 1.0 M HCl and water?"
Answer:
You first start by weighing a quatity of NaHCO3 which is by calculating the molecular mass of the salt and then multiply it with the molarity given which is 0.5 M, the gram/mol gotten is then dissolve in some water, add 0.1M NaOH dropwise until the pH is 9.8. Transfer quantitatively to a 100 mL volumetric flask and dilute to the mark. Mix thoroughtly.
Explanation:
molar mass of Na HCO3= 84.01
molarity given= 0.5 M
to get the g/mol to dissolve in 1000 mL , 0.5 x 84.01 =42.005 g/mol=1 L
to get 100 mL , 42.002 divide by 10
=4.2005g/mol
To make a carbonic acid buffer at 0.5 M and pH 6.0, mix equal molar amounts of NaHCO3 and H2CO3. For 100 mL at 0.5 M, mix 25 mL of 1.0 M HCl with 50 mL of 1.0 M NaHCO3 and dilute to 100 mL with water.
Explanation:To make 100 mL of a carbonic acid buffer at 0.5 M and pH = 6.0 using 1.0 M NaHCO3 and either 1.0 M NaOH or 1.0 M HCl, you first need to understand the Henderson-Hasselbalch equation:
pH = pKa + log([A-]/[HA])
For carbonic acid (pKa ≈ 6.1), when pH is 6.0:
6.0 = 6.1 + log([NaHCO3]/[H2CO3])
This suggests the ratio of [NaHCO3] to [H2CO3] should be close to 1:1. Solving for the concentrations:
log([NaHCO3]/[H2CO3]) = -0.1
[NaHCO3]/[H2CO3] ≈ 0.79
If you want a 0.5 M buffer, you'll need close to 0.25 M NaHCO3 and 0.25 M H2CO3.
To get H2CO3, you can add HCl to NaHCO3 since H2CO3 is not stable:
NaHCO3 + HCl → H2CO3 + NaCl
For 100 mL at 0.25 M, you would need 25 mmol of HCl. You would take 25 mL of 1.0 M HCl (because 25 mL × 1.0 M = 25 mmol) and add it to 50 mL of 1.0 M NaHCO3 (which provides 50 mmol NaHCO3) to keep the ratio. Then dilute to 100 mL with water.
Draw the Lewis structure for the disulfur monoxide molecule. Be sure to include all resonance structures that satisfy the octet rule.
The Lewis structure for disulfur monoxide, S2O, involves establishing eighteen valence electrons from the two sulfur atoms and the oxygen atom. The resulting structure shows each sulfur atom bonded to the central oxygen atom in a resonance structure, with each atom satisfying the octet rule.
Explanation:To draw the Lewis structure for disulfur monoxide (S2O), we begin by determining the total number of valence electrons. Sulfur has six, and with two sulfur atoms, that gives us twelve. Oxygen also has six valence electrons. So, the total is eighteen.
Next, we arrange the atoms to show the skeletal structure. For S2O, both sulfur atoms are bonded to the oxygen atom in the center. This behaves as a resonance structure. We then distribute the remaining electrons so each sulfur has eight: S-S=O
Note that each sulfur atom ends up with eight electrons (an octet), and the oxygen atom also has eight electrons.
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The Lewis structure of disulfur monoxide (S2O) has two sulfur atoms at the center, each connected by a single bond and an oxygen atom connected to a sulfur atom by a single bond. All elements fulfill the octet rule with the current structure and thus no resonance structure is required.
Explanation:The question is asking about the Lewis structure for the molecule disulfur monoxide (S2O). To create the Lewis structure, first count the number of valence electrons. Sulfur has 6 and oxygen has 6, so there is a total of 18 valence electrons in the molecule. We place sulfur atoms as the central atoms connected by a single bond and then place the oxygen atom adjacent to one of the sulfur atoms, also connected by a single bond.
Then, let's distribute remaining electrons to each atom to satisfy the octet rule. If there are too many electrons in the structure, make multiple bonds between S and O. However, in this case, S2O molecule can fully satisfy the octet rule with just single bonds. Double bonds are not needed. Similarly, there are no resonance structures for S2O according to the octet rule, as all the atoms achieve their necessary eight electrons with the initial structure.
Learn more about Lewis structure here:https://brainly.com/question/20300458
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Student mixed 25.0 mL of 0.100 M glucose, 15.0 mL of 0.500 M NaCl and 450. mL water. What are concentrations in his solution?
The question is incomplete, here is the complete question:
Student mixed 25.0 mL of 0.100 M glucose, 15.0 mL of 0.500 M NaCl and 450. mL water. What are concentrations in his solution?
A. 5.10 mM glucose, 15.3 mM NaCl
B. 5.56 mM glucose, 16.7 mM NaCl
C. 0.556 mM glucose, 0.167 mM NaCl
D. 0.222 mM glucose, 1.11 mM NaCl
E. 0.556 mM glucose, 0.0667 mM NaCl
Answer: The concentration of glucose and NaCl in the solution is 5.10 mM and 15.3 mM respectively.
Explanation:
To calculate the number of moles for given molarity, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}[/tex] .....(1)
For glucose:Molarity of glucose solution = 0.100 M
Volume of solution = 25.0 mL
Putting values in equation 1, we get:
[tex]0.100M=\frac{\text{Moles of glucose}\times 1000}{25.0}\\\\\text{Moles of glucose}=\frac{(0.100\times 25.0)}{1000}=0.0025mol[/tex]
For NaCl:Molarity of NaCl solution = 0.500 M
Volume of solution = 15.0 mL
Putting values in equation 1, we get:
[tex]0.500M=\frac{\text{Moles of NaCl}\times 1000}{15.0}\\\\\text{Moles of NaCl}=\frac{(0.500\times 15.0)}{1000}=0.0075mol[/tex]
Total volume of solution = 25.0 + 15.0 + 450. = 490. mL
Now, calculating the concentration of glucose and NaCl in the solution by using equation 1:
Using conversion factor: 1 M = 1000 mM
For glucose:Moles of glucose = 0.0025 moles
Volume of solution = 490. mL
Putting values in equation 1, we get:
[tex]\text{Concentration of glucose}=\frac{0.0025\times 1000}{490}\\\\\text{Concentration of glucose}=0.0051M=5.10mM[/tex]
For NaCl:Moles of NaCl = 0.0075 moles
Volume of solution = 490. mL
Putting values in equation 1, we get:
[tex]\text{Concentration of NaCl}=\frac{0.0075\times 1000}{490}\\\\\text{Concentration of NaCl}=0.0153M=15.3mM[/tex]
Hence, the concentration of glucose and NaCl in the solution is 5.10 mM and 15.3 mM respectively.
Calculate the volume in liters of a 0.360 mol/l barium acetate solution that contains 100.g of barium acetate (Ba(C2H3O2)2) . Round your answer to 3 significant digits.
Answer:
1.08 liters is the volume of 100 g of Ba(CH₃COO)₂
Explanation:
This data is a sort of concentration (Molarity) → 0.360 M [Ba(CH₃COO)₂]
It means that 0.36 moles of solute are contained in 1L of solution.
We should determine the moles of salt, that corresponds to 100 g of solute.
Mass / Molar mass
Ba(CH₃COO)₂ molar mass = 255.3 g/m
100 g / 255.3 g/m = 0.391 moles
So, we can apply a rule of three to calculate the volume of salt.
0.360 moles of solute are contained in 1L of solution
0.391 would be contained in (0.391 .1) / 0.360 = 1.08 liters