20 mL of an approximately 10% aqueous solution of ethylamine, CH3CH2NH2, is titrated with 0.3000 M aqueous HCl. Which indicator would be most suitable for this titration? The pKa of CH3CH2NH3+ is 10.75.
Answer:
Bromocresol green, color change from pH = 4.0 to 5.6
Explanation:
The equation for the reaction is as follows:
[tex]C_2H_5NH_{2(aq)[/tex] + [tex]H^+_{(aq)[/tex] ⇄ [tex]C_2H_5NH_{3(aq)}^+[/tex]
Given that concentration of [tex]C_2H_5NH_{2(aq)[/tex] = 10%
i.e 10 g of [tex]C_2H_5NH_{2(aq)[/tex] in 100 ml solution
molar mass = 45.08 g/mol
number of moles = [tex]\frac{10}{45.08}[/tex]
= 0.222 mol
Molarity of [tex]C_2H_5NH_{2(aq)[/tex] = 0.222 × [tex]\frac{1000}{100}mL[/tex]
= 2.22 M
However, number of moles of [tex]C_2H_5NH_{2(aq)[/tex] in 20 mL can be determined as:
number of moles of [tex]C_2H_5NH_{2(aq)[/tex] = 20 mL × 2.22 M
= [tex]44*10^{-3} mole[/tex]
Concentration of [tex]C_2H_5NH_{2(aq)[/tex] = [tex]\frac{44*10^{-3}*1000}{20}[/tex]
= 2.22 M
Similarly, The pKa Value of [tex]C_2H_5NH_{2(aq)[/tex] is given as 10.75
pKb value will be: 14 - pKa
= 14 - 10.75
= 3.25
Finally, the pH value at equivalence point is:
pH= [tex]\frac{1}{2}pKa - \frac{1}{2}pKb-\frac{1}{2}log[C][/tex]
pH = [tex]\frac{14}{2}-\frac{3.25}{2}-\frac{1}{2}log [2.22][/tex]
pH = 5.21
∴
The indicator that is best fit for the given titration is Bromocresol Green Color change from pH between 4.0 to 5.6.
For titration of the weak base ethylamine with a strong acid like HCl, the pH at the equivalence point will be less than 7, so an indicator that changes color in an acidic pH range such as methyl orange would be most suitable.
Explanation:The appropriate indicator in this case would depend on the equivalence point of the titration. Ethylamine, CH3CH2NH2, is a weak base, and it's being titrated with HCl, a strong acid. The reaction between them generates water, and ethylammonium chloride which functions as a weak acid. This setup indicates that the pH at the equivalence point will be less than 7.
Because the pH at the equivalence point will be in the acidic range (below 7), we should select an indicator which changes color around this pH. A good choice would be methyl orange, which changes color from red to yellow across a pH range of approximately 3.1 to 4.4.
Learn more about Titration of Weak Base with Strong Acid here:https://brainly.com/question/31866473
#SPJ3
Consider a culture medium on which only gram-positive organisms such as Staphylococcus aureus colonies can grow due to an elevated NaCl level. A yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the pH as a result and changing the color of a pH indicator chemical. This type
Explanation:
Selective media allow specific types of organisms to develop, and inhibit the development of different living beings. The selectivity is cultivated in a few ways.For model, living beings that can use a given sugar are handily screened by making that sugar the main carbon source in the medium. On the other hand,selective hindrance of certain sorts of microorganisms can be accomplished by adding dyes, anti-infection agents, salts or explicit inhibitors which influence the digestion or enzyme systems of the living beingsDifferential media are utilized to separate firmly related life forms or groups of living beings. owing to the pre of specific colors or synthetic compounds in the media, the creatures will deliver trademark changes or development designs that are utilized for ID or separation. An assortment of particular and differential media are utilized in clinical, demonstrative and water contamination research facilities, and in food and dairy laboratoriesSelective media because elevated NaCI level is designed to help grow selective bacteria.differential media because the fermented sugar gives off a yellow halo which allows for differentiate between bacteriaConsider a cup of coffee that has a temperature of 93 oC. Assume the mass of the coffee is 550 g and that the specific heat of coffee is about the same as the specific heat of the water. Is a 230 g ice cube (at 0 oC) a large enough ice cube to bring the temperature of the coffee to 23 oC?
Answer:
The answer to your question is No, is not enough
Explanation:
I attached the problem because it says that my answer has bad words.
Consider the decomposition of the compound C5H6O3 as follows below. C5H6O3(g) → C2H6(g) + 3 CO(g) When a 5.63-g sample of pure C5H6O3(g) was sealed into an otherwise empty 2.50 L flask and heated to 200.°C, the pressure in the flask gradually rose to 1.63 atm and remained at that value. Calculate K for this reaction.
Answer:
K = 6.5 × 10⁻⁶
Explanation:
C₅H₆O₃(g) → C₂H₆(g) + 3 CO(g)
The formula for the ideal gas law
PV = nRT
where
P = total pressure
V = volume
n = total moles
R = gas constant
T = absolute temperature
P(C₅H₆O₃) = nRT/V
where
n = 5.63 /114
= 0.049
[tex]= \frac{0.049 * 0.0821 * 473}{2.5}[/tex]
= [tex]0.78atm[/tex]
C₅H₆O₃(g) ⇄ C₂H₆(g) + 3 CO(g)
0.78atm 0 0
0.78 - x x 3x
P(total) = 1.63atm
0.78atm - x + x + 3x⇒x = 0.288atm
P(C₅H₆O₃) = 0.78 - 0.288
= 0.489 atm
P(C₂H₆) = 0.288 atm
P(CO) = 0.846 atm
[tex]Kp = \frac{0.288 * 0.864^3}{0.489}[/tex]
= 0.379
K = Kp/(RT³)
[tex]= \frac{0.379}{(0.0821 * 473)^3} \\= 6.5 * 10^-^6[/tex]
K = 6.5 × 10⁻⁶
The value of K for this reaction is : 6.5 * 10⁻⁶
The decomposition equation
C₅H₆O₃ ----> C₂H₆ (g) + 3 CO (g)
Given data :
mass of pure C₅H₆O₃ = 5.63 g
volume of flask = 2.50 L
Temperature = 200°C = 473 K
Pressure in flask = 1.63 atm
Determine the value of K for this reactionwe will apply Ideal gas law formula
PV = nRT
therefore P( C₅H₆O₃ ) = nRT / V ---- ( 1 )
where : n = 5.63 / 114 = 0.049, V = 2.5 L, R = 0.0821, T = 473 k
Insert values into equation ( 1 )
P( C₅H₆O₃ ) = 0.78 atm - x ---- ( 2 )
P(total) = 1.63 atm.
Considering the decomposition equation
0.78 - x + x + 3x = 1.63 atm
therefore ; x = 0.288
back to equation ( 2 )
P( C₅H₆O₃ ) = 0.78 - 0.288 = 0.489 atm
Given that :
P(C₂H₆) = 0.288 atm
P(CO) = 0.846 atm
Find K using the relationship below
K = Kp / ( RT)³ ------ ( 3 )
While Kp = ( 0.288 * 0.864³ ) / 0.489
= 0.379
Back to equation ( 3 )
K = 0.379 / ( 0.0821 * 473 )³
= 6.5 × 10⁻⁶.
Hence we can conclude that the value of K for this reaction is : 6.5 * 10⁻⁶
Learn more about decomposition : https://brainly.com/question/14219426
5. Explain in your own words what the author means when he says that “on a molecular level, no one compound is grosser than any other.”
On a molecular level, the author means that no compound is grosser than any other, as all compounds are made up of the same fundamental building blocks: atoms and molecules.
Explanation:The author means that, on a molecular level, no one compound is inherently more disgusting or repulsive than another. This statement suggests that all compounds, regardless of their odor, appearance, or taste, are made up of the same fundamental building blocks: atoms and molecules. For example, two compounds may have different smells, but they are both composed of the same elements and bond together in similar ways. So, while certain compounds may be perceived as gross or unpleasant to our senses, from a molecular standpoint, they are all equally fascinating and interconnected.
Unit mass is measured in...
Answer: The kilogram is the SI unit of mass and it is the almost universally used standard mass unit.
Explanation: When we use kilograms to measure weight, we are actually referring to kgf or kilogram-force.
Write the balanced net ionic equation for the reactions that occur when the given aqueous solutions are mixed. Include the physical states. A. silver nitrate, AgNO 3 AgNO3 , and magnesium bromide, MgBr 2 MgBr2 net ionic equation: B. perchloric acid, HClO 4 HClO4 , and potassium hydroxide, KOH KOH net ionic equation: C. ammonium sulfide, ( NH 4 ) 2 S (NH4)2S , and cobalt(II) chloride, CoCl 2 CoCl2 net ionic equation:
Answer : The balanced net ionic equation for the reactions are:
(A) [tex]2Ag^{+}(aq)+2Br^{-}(aq)\rightarrow AgBr(s)[/tex]
(B) [tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]
(C) [tex]Co^{2+}(aq)+S^{2-}(aq)\rightarrow CoS(s)[/tex]
Explanation :
Complete ionic equation : In complete ionic equation, all the substance that are strong electrolyte and present in an aqueous are represented in the form of ions.
Net ionic equation : In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
Part A :
The balanced molecular equation will be,
[tex]2AgNO_3(aq)+MgBr_2(aq)\rightarrow Mg(NO_3)_2(aq)+2AgBr(s)[/tex]
The complete ionic equation in separated aqueous solution will be,
[tex]2Ag^+(aq)+2NO_3^{-}(aq)+Mg^{2+}(aq)+2Br^{-}(aq)\rightarrow Mg^{2+}(aq)+2NO_3^{-}(aq)+2AgBr(s)[/tex]
In this equation the species [tex]Mg^{2+}\text{ and }NO_3^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]2Ag^{+}(aq)+2Br^{-}(aq)\rightarrow AgBr(s)[/tex]
Part B :
The balanced molecular equation will be,
[tex]HClO_4(aq)+KOH(aq)\rightarrow H_2O(l)+KClO_4(aq)[/tex]
The complete ionic equation in separated aqueous solution will be,
[tex]H^+(aq)+ClO_4^{-}(aq)+K^{+}(aq)+OH^{-}(aq)\rightarrow K^{+}(aq)+CLO_4^{-}(aq)+H_2O(l)[/tex]
In this equation the species [tex]K^{+}\text{ and }ClO_4^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]
Part C :
The balanced molecular equation will be,
[tex](NH_4)_2S(aq)+CoCl_2(aq)\rightarrow 2NH_4Cl(aq)+CoS(s)[/tex]
The complete ionic equation in separated aqueous solution will be,
[tex]2NH_4^+(aq)+S^{2-}(aq)+Co^{2+}(aq)+2Cl^{-}(aq)\rightarrow 2NH_4^{+}(aq)+2Cl^{-}(aq)+CoS(s)[/tex]
In this equation the species [tex]NH_4^{+}\text{ and }Cl^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]Co^{2+}(aq)+S^{2-}(aq)\rightarrow CoS(s)[/tex]
Final answer:
The net ionic equations are: 2Ag+ + 2Br- -> 2AgBr(s); H+ + OH- -> H2O(l); Co2+ + S2- -> CoS(s).
Explanation:
The net ionic equation for the reaction between silver nitrate (AgNO3) and magnesium bromide (MgBr2) is:
2Ag+ + 2Br- -> 2AgBr(s)
The net ionic equation for the reaction between perchloric acid (HClO4) and potassium hydroxide (KOH) is:
H+ + OH- -> H2O(l)
The net ionic equation for the reaction between ammonium sulfide ((NH4)2S) and cobalt(II) chloride (CoCl2) is:
Co2+ + S2- -> CoS(s)
Suppose a group of volunteers is planning to build a park near a local lake. The lake is known to contain low levels of arsenic (As). Therefore, prior to starting construction, the group decides to measure the current level of arsenic in the lake.A) If a 15.7 cm3 sample of lake water is found to have 164.5 ng As, what is the concentration of arsenic in the sample in parts per billion (ppb), assuming that the density of the lake water is 1.00 g/cm3?
B) Calculate the total mass (in kg) of arsenic in the lake that the company will have to remove if the total volume of water in the lake is 0.710 km3?
C) Based on the company\'s claim and the concentration of arsenic in the lake, how many years will it take to remove all of the arsenic from the lake, assuming that there are always 365 days in a year?
A) 10.75 is the concentration of arsenic in the sample in parts per billion .
B) 7,633.66 kg the total mass of arsenic in the lake that the company have to remove.
C)It will take 1.37 years to remove all of the arsenic from the lake.
Explanation:
A) Mass of arsenic in lake water sample = 164.5 ng
The ppb is the amount of solute (in micrograms) present in kilogram of a solvent. It is also known as parts-per million.
To calculate the ppm of oxygen in sea water, we use the equation:
[tex]\text{ppb}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^9[/tex]
Both the masses are in grams.
We are given:
Mass of arsenic = 164.5 ng = [tex]164.5\times 10^{-9} g[/tex]
[tex]1 ng=10^{-9} g[/tex]
Volume of the sample = V = [tex]15.3 cm^3[/tex]
Density of the lake water sample ,d= [tex]1.00 g/cm^3[/tex]
Mass of sample = M = [tex]d\times V=1.0 g/cm^3\times 15.3 cm^3=15.3 g[/tex]
[tex]ppb=\frac{164.5\times 10^{-9} g}{15.3 g}\times 10^9=10.75[/tex]
10.75 is the concentration of arsenic in the sample in parts per billion.
B)
Mass of arsenic in [tex]1 cm^3[/tex] of lake water = [tex]\frac{164.5\times 10^{-9} g}{15.3}=1.075\times 10^{-8} g[/tex]
Mass of arsenic in [tex]0.710 km^3[/tex] lake water be m.
[tex]1 km^3=10^{15} cm^3[/tex]
Mass of arsenic in [tex]0.710\times 10^{15} cm^3[/tex] lake water :
[tex]m=0.710\times 10^{15}\times 1.075\times 10^{-8} g=7,633,660.130 g[/tex]
1 g = 0.001 kg
7,633,660.130 g = 7,633,660.130 × 0.001 kg=7,633.660130 kg ≈ 7,633.66 kg
7,633.66 kg the total mass of arsenic in the lake that the company have to remove.
C)
Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.
Days required to remove 1 kilogram of arsenic from the lake water :
[tex]\frac{2.74}{41.90} days[/tex]
Then days required to remove 7,633.66 kg of arsenic from the lake water :
[tex]=7,633.66\times \frac{2.74}{41.90} days=499.19 days[/tex]
1 year = 365 days
499.19 days = [tex]\frac{499.19}{365} years = 1.367 years\approx 1.37 years[/tex]
C)
Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.
Days required to remove 1 kilogram of arsenic from the lake water :
[tex]\frac{2.74}{41.90} days[/tex]
Then days required to remove 7,633.66 kg of arsenic from the lake water :
[tex]=7,633.66\times \frac{2.74}{41.90} days=499.19 days[/tex]
1 year = 365 days
499.19 days = [tex]\frac{499.19}{365} years = 1.367 years\approx 1.37 years[/tex]
It will take 1.37 years to remove all of the arsenic from the lake.
The concentration of arsenic in the lake water sample is 10.5 ppb. The total mass of arsenic in the entire lake is 7445 kg. However, the time required to remove all arsenic from the lake cannot be calculated as the daily removal rate is not specified.
Explanation:To compute the concentration of arsenic in the sample in parts per billion (ppb), we first need to convert the mass of arsenic from ng to g. This gives us 164.5 ng x 10^-9 = 1.645 x 10^-7 g. Given that the density of the water is 1 g/cm^3 = 1 g/mL, a sample of 15.7 cm^3 would weigh 15.7 g. so, the concentration in ppb would be: (1.645 x 10^-7 g / 15.7 g) x 10^9 = 10.5 ppb.
Next, to find the total mass of arsenic in the whole lake, first convert the volume of the lake to cm^3. 0.710 km^3 = 0.710 x 10^15 cm^3. Using the concentration we found earlier, the total mass of arsenic (in g and then in kg) is (10.5 ppb x 0.710 x 10^15 g) x 10^-9 = 7445 kg of arsenic.
Finally, the time to remove all of the arsenic will depend on how much arsenic the company can remove per day, which is not mentioned in the problem. Thus, we can't calculate it based on the information given.
Learn more about Arsenic Concentration here:https://brainly.com/question/34444452
#SPJ3
For the reaction of A and B forming C, A(g)+ B(s)⇌ 2C(g) how will the reaction respond to each of the following changes at equilibrium? Drag the appropriate items to their respective bins.
a) double the concentration of B and halve the concentration of C.
b) double the concentrations of both products and then quadruple the container volume.
c) double the container volume.
d) double the concentrations of both products.
e) add more A.
f) double the concentrations of both products and then double the container volume.
The effects of changes in concentrations or volume on an equilibrium are predicted by Le Chatelier's principle. The reaction will typically shift to restore equilibrium in response to such changes. The exact direction of the shift depends on the specifics of the change in conditions.
Explanation:This question refers to Le Chatelier's principle, which allows predictions about how a change in conditions will affect a chemical equilibrium. (a) By doubling the concentration of B and halving the concentration of C, you are disrupting the equilibrium. The reaction will shift to the right (towards C) to reestablish equilibrium. (b) Doubling the concentrations of both products and quadrupling the container volume will decrease pressure, and the reaction will shift towards the side with more moles of gas, which is the right in this case. (c) Doubling the container's volume also reduces the pressure, again causing the reaction to shift to the right. Likewise, (d) the increase of products will shift the equilibrium to the left to minimize the effect. (e) Adding more A will cause the reaction to shift to the right, resulting in the formation of more C. (f) Doubling the concentrations of both the products and the container volume has two opposing effects. The added products would shift the reaction to the left, while the increased volume would shift it to the right. Thus, the final shift in equilibrium is dependent on which effect is greater.
Learn more about Le Chatelier's principle here:https://brainly.com/question/33440831
#SPJ3
The equilibrium of the reaction A(g) + B(s) \<=> 2C(g) will shift to counteract changes such as concentration and volume adjustments, consistent with Le Chatelier's principle.
The response of the reaction A(g) + B(s) \<=> 2C(g) at equilibrium to various changes can be explained by Le Chatelier's principle, which states that a system at equilibrium will adjust to minimize any changes applied to it.
(a) If the concentration of B is doubled and the concentration of C is halved, the reaction would shift towards producing more C to counteract the decrease in C and to use up the extra B.(b) Doubling the concentrations of both products and then quadrupling the container volume will cause the reaction to shift left in order to increase pressure, thus favouring the side with more moles of gas, which is the reactants' side.(c) Doubling the container volume will decrease the pressure, so the reaction will shift towards producing more gas, thus shifting to the right towards more C.(d) Doubling the concentrations of both products will shift the equilibrium to the left, to reduce the concentration of the products and form more reactants.(e) Adding more A will shift the equilibrium to the right, to form more products and reduce the increased concentration of A.(f) Doubling the concentrations of both products and then doubling the container volume will have the net effect of no change in concentration due to volume change, but the initial doubling of products will still cause a left shift in the equilibrium.Which aqueous solution of KI freezes at the lowest temperature?
a. 1 mol of KI in 500. g of water
b. 2 mol of KI in 500. g of water
c. 1 mol of KI in 1000. g of water
d. 2 mol of KI in 1000. g of water
Answer:
b. 2 mol of KI in 500. g of water
Explanation:
We have to apply the colligative property of freezing point depression.
The formula is: ΔT = Kf . m . i
As the (Kf . m . i) is higher, then the freezing temperature will be lower.
i refers to the Van't Hoff factor (number of ions dissolved in the solution)
KI → K⁺ + I⁻ (i =2)
Kf is constant so, we have to search for the highest m (molality)
Molality means the moles of solute in 1kg of solvent.
The highest m is option b → 2 mol of KI / 0.5 kg = 4 mol/kg
a. 1 mol of KI / 0.5 kg = 2 mol/kg
c. 1 mol of KI / 1kg = 1 mol/kg
d. 2 mol of KI / 1kg = 2 mol/kg
1000 g = 1kg. In order to determine molality we need to convert the mass (g) of solvent to kg
The density of potassium, which has the BCC structure, is 0.855 g/cm3. The atomic weight of potassium is 39.09 g/mol. Calculate (a) the lattice parameter; and (b) the atomic radius of potassium
Answer:
lattice parameter = 5.3355x10^-8 cm
atomic radius = 2.3103x10^-8 cm
Explanation:
known data:
p=0.855 g/cm^3
atomic mass = 39.09 g/mol
atoms/cell = 2 atoms
Avogadro number = 6.02x10^23 atom/mol
a) the lattice parameter:
Since potassium has a cubic structure, its volume is equal to:
v = [(atoms/cell)x(atomic mass)/(p)x(Avogadro number)]
substituting values:
v =[(2)x(39.09)/(0.855x6.02x10^23)]=1.5189x10^-22 cm^3
but as the cell volume is
a^3 =v
[tex]a=\sqrt[3]{v}=\sqrt[3]{1.5189x10^{-22} } = 5.3355x10^-8[/tex] cm
for a BCC structure, the atomic radius is equal to
[tex]r=\frac{ax\sqrt{3} }{4}=\frac{5.3355x10^{-8}x\sqrt{3} }{4}=2.3103x10^{-8}cm[/tex]
A compound was determined to have the simplest formula CH2. If the molecular weight of the compound is 70 u, what is the molecular formula of the compound? 1. C5H10 2. C10H5 3. C4H22 4. C4H8
Answer:
The answer to your question is letter A
Explanation:
Data
Empirical formula CH₂
Molecular weight = 70 u
Process
1.- Calculate the molecular weight of the empirical formula (CH₂)
CH₂ = (12 x 1) + (1 x 2) = 12 + 2 = 14 g
2.- Divide the molecular weight by the molecular weight of the empirical formula
70/14 = 5
3.- Write the empirical formula
5(C₁H₂) = C₅H₁₀
1. C₅H₁₀
Given:
Empirical formula = CH₂
Molecular weight = 70 u
To find Molecular formula of the compound:
1.- Calculate the molecular weight of the empirical formula (CH₂)
CH₂ = [tex](12 * 1)+(1*2)=12+2=14 u[/tex]
(As molecular weight of C=12u and H= 1u)
2.- Divide the molecular weight by the molecular weight of the empirical formula
[tex]\frac{\text{Molecular weight}}{\text{ Molecular weight of Empirical formula}} = \frac{70}{14} =5[/tex]
3.- Write the empirical formula
5(C₁H₂) = C₅H₁₀
Learn more:
brainly.com/question/15960587
A sample of nitrogen goes from 21L to 14L and it's pressure increases from 100kPa to 150kPa. The final temperature is 300K. What was the initial temperature in Kelvins?
Answer:
The initial temperature is 300 K (The temperature doesn't change)
Explanation:
Step 1: Data given
Initial volume = 21L
Final volume = 14L
Initial pressure = 100 kPa = 0.986923 atm
Final pressure = 150 kPa = 1.48038 atm
The final temperature = 300K
Step 2: Calculate the initial temperature
Calculate the initial temperature
(P1*V1)/T1 = (P2*V2)/T2
⇒with P1 = the initial pressure = 0.986923 atm
⇒with V1 = the initial volume = 21 L
⇒ with T1 = the initial temperature = ?
⇒with P2 = the final pressure = 1.48038 atm
⇒with V2 = the final volume = 14 L
⇒with T2 = the final temperature = 300 K
(0.986923 * 21)/T1 = (1.48038*14)/300
T1 = 300 K
The initial temperature is 300 K (The temperature doesn't change)
Nalorphine (c19h21no3), a relative of morphine, is used to combat withdrawal symptoms in narcotics users. how many grams of a 1.3 x 10-3 m aqueous solution of nalorphine are needed to obtain a dose of 1.5 mg?
Answer:
3.7g
Explanation:
First we calculate the molar mass of the drug. Secondly, we now obtain the mass of the drug solution required at the given concentration to obtain a 1.5 milligram dose of the drug. The substitution is now properly done and the mass is obtained as 3.7g of the nalorphine drug which is a relative or morphine used to combat withdrawal symptoms in narcotic users.
A 60g sample of tetraethyl lead, a gasoline additive, is found to contain 38.43g lead, 17.83g carbon and 3.74g hydrogen. Determine the compounds empirical formula.
Answer:
Empirical formula (which matches the molecular formula) is = PbC₈H₂₀
Explanation:
Our sample: 60 g of tetraethyl lead
In order to determine the compound empirical formula we need the centesimal composition:
(Mass of element / Total mass) . 100 =
(38.43 g lead / 60g ) . 100 = 64.05%
(17.83 g C / 60g) . 100 = 29.72%
(3.74 g H / 60g) . 100 = 6.23 %
These % are the mass of the elements in 100 g of compound. Let's find out the moles of them:
64.05 g / 207.2 g/mol = 0.309 moles
29.72 g / 12 g/mol = 2.48 moles
6.23 g/ 1 g/mol = 6.23 moles
Next, we divide the moles, by the lowest value of them (0.309)
0.309 / 0.309 = 1 mol Pb
2.48 / 0.309 = 8 mol C
6.23 / 0.309 = 20 mol H
There, we have our formula PbC₈H₂₀
Zinc reacts with hydrochloric acid according to the reaction equation Zn ( s ) + 2 HCl ( aq ) ⟶ ZnCl 2 ( aq ) + H 2 ( g ) How many milliliters of 5.00 M HCl ( aq ) are required to react with 3.15 g Zn ( s ) ?
Answer:
We need 19.3 mL of HCl
Explanation:
Step 1: Data given
Molarity HCl = 5.00 M
Mass Zn = 3.15 grams
Step 2: The balanced equation
Zn (s) + 2HCl (aq) ⟶ ZnCl2 (aq) + H2 (g)
Step 3: Calculate moles Zn
Moles Zn = mass Zn / molar mass Zn
Moles Zn = 3.15 grams / 65.38 g/mol
Moles Zn = 0.0482 moles
Step 4: Calculate moles HCl needed
For 2 moles HCl we need 1 mol Zn to produce 1 mol ZnCl2 and 1 mol H2
For 0.0482 moles Zn we need 2*0.0482 = 0.0964 moles HCl needed
Step 5: Calculate volume needed
Molarity = moles / volumes
Volumes = moles / molarity
Volume HCl needed = 0.0964 moles HCl /5.00 M
Volume HCl needed = 0.01928 L = 19.3 mL
We need 19.3 mL of HCl
The balanced chemical equation for the combustion of hexane is:2C6H14(g) + 19O2(g) The balanced chemical equation for the combustion 12CO2(g) + 14H2O(g)Answer the question in Part 1 through Part 3, if the rate of reaction of C6H14 is 1.43 mol L-1s-1. The rate of reaction of C6H14 is the rate of disappeareance of C6H14.1. What was the rate of formation of CO2?2. What was the rate of formation of H2O?3. What is the rate of reaction of O2?
Answer:
The rate of formation of CO2 = 1.43 mol L-1s-1.
The rate of formation of H2O = 1.43 mol L-1s-1.
The rate of reaction of O2 = 1.43 mol L-1s-1.
Explanation:
2C6H14(g) + 19O2(g) -------> 12CO2(g) + 14H2O(g)
The rate of reaction of C6H14 is 1.43 mol L-1s-1.
The rate of reaction is theoretically defined as the speed of a chemical reaction. It is how fast or how slow the reactants are being used up or products are being formed.
It is the rate of change of concentration, amount etc., of any of the reactant or any of the product with time. The rate of reaction is the same and uniform for any of the products and reactants.
For a chemical reaction, A + 2B -----> 2C
r = -(dA/dt) = -(dB/dt) = (dC/dt)
Hence, the rate of reaction = rate of disappearance of C6H14 = rate of formation of CO2 = rate of formation of H2O = rate of reaction of O2 = 1.43 mol L-1s-1.
Hope this Helps!!!
The maximum number of electrons that are possible at a given energy level depends on the number of ____ at the energy level.
Answer:
orbitalsExplanation:
Each orbital may contain a maximum of two electrons.
The energy level is the principal quantum number: 1, 2, 3, 4, 5, 6, 7.
The principal quantum number limits the kind of orbital (ℓ ) and the number of orbitals (mℓ ).
I. Principal quantum number, n = 1
Angular or orbital quantum number : ℓ = 0 ⇒ ortibal s
Magnetic quantum number: mℓ = 0
⇒ number of orbitals 1 ⇒ number of electrons: 2
II. Principal quantun number, n = 2
Angular or orbital quantum number : ℓ = 0 and 1 ⇒ ortibal s and p
Magnetic quantum number:
for ℓ: mℓ = 0: 1 s ortibal
for ℓ = 1: mℓ = -1, 0, and +1: 3 p ortitals
⇒ number of orbitals 4 ⇒ number of electrons: 8
III. Principal quantun number, n = 3
Angular or orbital quantum number : ℓ = 0, 1, and 2 ⇒ ortibal s, p and d
Magnetic quantum number:
for ℓ: mℓ = 0: 1 s ortibal
for ℓ = 1: mℓ = -1, 0, and +1: 3 p ortitals
for ℓ = 2: mℓ = -2, -1, 0, +1, and +2: 5 d ortitals
⇒ number of orbitals 9 ⇒ number of electrons: 18
IV. Principal quantun number, n = 4
Angular or orbital quantum number : ℓ = 0, 1, 2, and 3 ⇒ ortibal s, p, d and f
Magnetic quantum number:
for ℓ: mℓ = 0: 1 s ortibal
for ℓ = 1: mℓ = -1, 0, and +1: 3 p ortitals
for ℓ = 2: mℓ = -2, -1, 0, +1, and +2: 5 d ortitals
for ℓ = 3: mℓ = ±3, ±2, ±1, and 0: 7 f ortitals
⇒ number of orbitals 16 ⇒ number of electrons: 32.
Thus, you have:
energy level, n maximum number of maximum number of
orbitals electrons
1 1 2
2 4 8
3 9 18
4 16 32
Those numbers follow a rule: n² and 2n². You can verify that the previous numbers are in accordance with those formulas.
A solution of permanganate is standardized by titration with oxalic acid (). It required 54.77 mL of the permanganate solution to react completely with 0.3577 g of oxalic acid. The unbalanced equation for the reaction is What is the molarity of the permanganate solution
Answer:
0.1814 M
Explanation:
From the balanced equation of reaction:
[tex]2MnO_4^- + 16H^+ + 5C_2H_4^{2-} --> 2Mn^{2+} + 10CO_2 + 8H_2O[/tex]
2 mole of the permanganate requires 5 moles of oxalic acid.
Mole of 0.3577 g of oxalic acid = [tex]\frac{mass}{molar mass}[/tex]
= 0.3577/90.03
=0.00397 mole
Mole of permangante that will require 0.00397 mole of oxalic acid:
= 5 x 0.00397/2
= 0.00993 mole
Molarity of permanganate = mole/volume
Volume of permanganate = 54.77 mL = 0.05477 L
Molarity = 0.00993/0.05477
= 0.1814 M
The molarity of the permangante solution is 0.1814 M
Answer:
See explanation below
Explanation:
The reaction between permanganate and oxalic acid, is a redox reaction, and this can be balance in acid medium or basic medium.
The reaction (without being balanced) is the following:
MnO₄⁻ + H₂C₂O₄ -------> Mn²⁺ + CO₂ + H₂O
Now, to get the molarity, we need to use the following expression:
M₁V₁ = M₂V₂ (1)
Where:
1: permanganate
2: oxalic acid
And the moles:
n = M*V (2)
However, expression (1) is only valid when the mole ratio between the two species, is the same (or 1:1). In this case, we do not know if the mole ratio is 1:1 because the reaction is unbalanced. Once the reaction is balanced we will see the mole ratio, and then, use the expression (1) to get the concentration.
Balancing the equation using the acid medium:
MnO₄⁻ + 8H⁺ + 5e⁻ -------> Mn²⁺ + 4H₂O Reduction
H₂C₂O₄ ------------> 2CO₂ + 2e⁻ + 2H⁺ Oxidation
Equalling both equations:
(MnO₄⁻ + 8H⁺ + 5e⁻ -------> Mn²⁺ + 4H₂O) *2
(H₂C₂O₄ ------------> 2CO₂ + 2e⁻ + 2H⁺) * 5
___________________________________
2MnO₄⁻ + 16H⁺ + 10e⁻ -------> 2Mn²⁺ + 8H₂O
5H₂C₂O₄ ------------> 10CO₂ + 10e⁻ + 10H⁺
____________________________________
2MnO₄⁻ + 5H₂C₂O₄ + 6H⁺ -------> 2Mn²⁺ + 10CO₂ + 8H₂O
This is the balanced equation. According to this, we can say that the mole ratio is 2:5, therefore expression (1) becomes:
2M₁V₁ = 5M₂V₂ ---> solving for M₁:
M₁ = 5M₂V₂ / 2V₁ (3)
Now that we know the expression, and the volume required, we need to get the concentration and volume of the acid. However, we do not know that, we only know the mass. So, we have to use the moles of oxalic acid to get the concentration. So replacing (2) in (3) we have:
M₁ = 5n₂ / 2V₁ (4)
Now, to get the moles, we need the molecular weight of the oxalic acid which is:
MM = (2*1) + (2*12) + (4*16) = 90 g/mol
The moles would be:
n = 0.3577 / 90 = 0.00397 moles
Finally, the concentration of the permanganate solution:
M₁ = 5*0.00397 / 2*0.05477
M₁ = 0.1812 M
Generally speaking, elements with high electronegativities are 1. nonmetals. 2. likely to form anions (except the noble gases). 3. All of these 4. easily reduced (except the noble gases).
Answer:
1. Nonmetals.
2. Likely to form anions (except the noble gases).
3. All of these
4. Easily reduced (except the noble gases).
Explanation:
Elements with high electronegativities are found towards the upper right corner of the Periodic Table. Thus, they have all the above properties.
Nonmetals.
Likely to form anions (except the noble gases).
All of these
Easily reduced (except the noble gases).
electronegativity can be regarded as chemical property that is been possessed by an element which gives description of the tendency that the atom or a functional group of that elements have to attract electrons toward itself. All electronegative elements posses the tendency which gives the enablement to form anions only although Noble gases are excepted from thisFluorine can be regarded as the most electronegative element electronegative elements are regarded as non-metals , such as Chlorine, Oxygen, Fluorine and otherselectronegative elements can be reduced easily during redox reactionIn the periodic table , Electronegativities of this elements tends to experience increase from left to right across.Therefore, Electronegative elements are known to be non-metals.
Learn more at: https://brainly.com/question/24403314?referrer=searchResults
Liquid nitrogen trichloride is heated in a 1.25−L closed reaction vessel until it decomposes completely to gaseous elements. The resulting mixture exerts a pressure of 773 mmHg at 86°C. What is the partial pressure of each gas in the container?
Answer:
N2= 193.25mmHg
Cl2= 579.75mmHg
Explanation:
Total number of moles=4
For N2 mole fraction=1/4
Partial pressure of N2= 1/4× 773= 193.25mmHg
For Cl2, mole fraction= 3/4
Partial pressure of Cl2= 3/4 × 773 = 579.75 mmHg
The correct partial pressures of each gas in the container are:
[tex]\[ P_{\text{N}_2} = \frac{2}{3} \times 773 \text{ mmHg} \] \[ P_{\text{Cl}_2} = \frac{1}{3} \times 773 \text{ mmHg} \][/tex]
To find the partial pressures of each gas, we use Dalton's Law of Partial Pressures, which states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each individual gas. The chemical equation for the decomposition of nitrogen trichloride (NCl3) is:
[tex]\[ 2\text{NCl}_3(l) \rightarrow 2\text{N}_2(g) + 3\text{Cl}_2(g) \][/tex]
From the stoichiometry of the balanced equation, we see that 2 moles of NCl3 decompose to form 2 moles of N2 and 3 moles of Cl2. Therefore, for every mole of NCl3 that decomposes, 1 mole of N2 and 1.5 moles of Cl2 are produced. This gives us a molar ratio of N2 to Cl2 of 2:3 or, simplified, 2 parts N2 for every 3 parts Cl2, which corresponds to a ratio of 2/5 for N2 and 3/5 for Cl2 in the mixture.
Since the total pressure of the mixture is 773 mmHg, we can calculate the partial pressure of each gas by multiplying the total pressure by the respective molar ratios:
For nitrogen (N2):
[tex]\[ P_{\text{N}_2} = \frac{2}{5} \times 773 \text{ mmHg} \] \[ P_{\text{N}_2} = \frac{2}{3} \times 773 \text{ mmHg} \][/tex]
For chlorine (Cl2):
[tex]\[ P_{\text{Cl}_2} = \frac{3}{5} \times 773 \text{ mmHg} \] \[ P_{\text{Cl}_2} = \frac{1}{3} \times 773 \text{ mmHg} \][/tex]
Thus, the partial pressure of nitrogen gas (N2) is[tex]\( \frac{2}{3} \times 773 \text{ mmHg} \)[/tex] , and the partial pressure of chlorine gas (Cl2) is [tex]\( \frac{1}{3} \times 773 \text{ mmHg} \)[/tex]. These are the partial pressures of each gas in the container after the decomposition of liquid nitrogen trichloride.
Draw the major organic product formed when the compound shown below undergoes a reaction with hno3 and h2so4.
Answer:
The solution is shown in the attached image to this answer.
Explanation:
The first attached image is the complete question.
The second attached image is the solution to the question.
The major organic product formed when the compound undergoes a reaction with HNO3 and H2SO4 is the corresponding nitro compound, specifically 2-nitrobenzoic acid.
When the given compound reacts with a mixture of concentrated nitric acid (HNO3) and concentrated sulfuric acid (H2SO4), it undergoes a nitration reaction. This reaction results in the substitution of a nitro group (-NO2) at the meta position (position 2) of the benzene ring, yielding 2-nitrobenzoic acid as the major product.
The concentrated sulfuric acid serves as a catalyst and helps in the generation of the nitronium ion (NO2+), which is the electrophile responsible for attacking the benzene ring. The nitro group is introduced as a substituent on the aromatic ring, and the carboxylic acid group (-COOH) remains intact. Overall, this reaction is a common method for introducing nitro groups onto aromatic rings and is widely used in organic synthesis for the preparation of various nitroaromatic compounds.
Learn more about compound here: https://brainly.com/question/32438604
#SPJ6
We observe a distant object in space and see that the spectral lines for hydrogen in the object's light appear at a shorter wavelength than normal. What does this tell us about the object
Answer:
This tells us the radial velocity of the object and that the object is approaching or coming towards us.
Explanation:
Certain chemicals radiate with particular wavelengths or colors when their temperature is raised or when they are charged electrically. Also observable are dark strokes separating the spectrum known as absorption lines
These spectral lines of chemicals are well known as stated above and from the phenomenon of Doppler effect, spectroscopy can be used to detect the movement of a distant object by the change of the emitted frequency of the wavelength
The Doppler effect is used in calculating the radial velocity of a distant object due to the fact that an approaching object compresses its emitted signal wavelength while a receding object has a longer wavelength than normal
What will be the equilibrium temperature when a 235 gg block of copper at 255 ∘C∘C is placed in a 155 gg aluminum calorimeter cup containing 875 gg of water at 16.0 ∘C∘C?
Answer:
The answer to the question is
The equilibrium temperature T = 22.016 °C
Explanation:
To solve the question, we note the given variables thus
Mass of copper block =235 grams
Temperature of the copper block = 255 °C
Mass of aluminium calorimeter cup = 155 g
Mass of water in calorimeter cup = 16 °C
Also we note the specific heat capacities of the materials involved in the question
Specific heat capacity of water = 4.186 joule/gram
Specific heat capacity of copper= 0.385 joule/gram
Specific heat capacity of aluminium = 0.900 joule/gram
There for from the first law of thermodynamics, energy is neither created nor destroyed but it changes from one form to another, we have
Heat lost by copper = heat gained by water and the calorimeter cup
Therefore we have
The equation for heat capacity =
mass * specific heat capacity * Temperature change = m·c·ΔT
therefore
m·c·ΔT for copper = m·c·ΔT for aluminium + m·c·ΔT for water
where ΔT on the left of the equation = Initial temperature - final temperature
while on the right ΔT = Final temperature - Initial temperature
and the final temperature in this case = the equilibrium temperature
255*0.385*(255 -T) = 155*0.9*(T-16) +875*4.186*(T-16)
Which gives the equilibrium temperature T = 22.016 °C
The equilibrium temperature when a 235 g copper block at 255 °C is placed in a 155 g aluminum calorimeter cup containing 875 g of water at 16.0 °C can be found by applying conservation of energy. The heat lost by the hot copper block is equal to the heat gained by the water and the aluminum calorimeter. By setting up and solving this equation, we can determine the final equilibrium temperature.
Explanation:In this calorimeter scenario, we have a hot copper block transferring its heat to the colder aluminum calorimeter and the water it contains. As per the law of conservation of energy, the heat lost by the hot copper block will be equal to the heat gained by the water and the aluminum calorimeter. We can express this mathematically as:
(mass of copper)x(specific heat of copper)x(temperature change of copper) = (mass of water)x(specific heat of water)x(temperature change of water) + (mass of aluminum)x(specific heat of aluminum)x(temperature change of aluminum).
Given the specific heat of aluminum is 0.897 J/g °C, water is 4.184 J/g °C and copper is 0.390 J/g °C, we can substitute these values, as well as the rest of given values, into the equation and solve for the common final temperature, which represents the equilibrium temperature.
Learn more about Calorimetry here:https://brainly.com/question/34432277
#SPJ11
When one pair of electrons is shared between two atoms, a ______ bond is formed.
Answer: covalent bond
Explanation:
An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element or the metal and the element which accepts the electrons is known as electronegative element or non metal. Example: [tex]NaCl[/tex]
A covalent bond is formed when an element shares its valence electron with another element. This bond is formed between two non metals. Example: [tex]F_2[/tex] which is formed by sharing of one electron each from flourine atom.
A covalent bond is formed when one pair of electrons is shared between two atoms. This bond helps the atoms to complete their valence shell. Multiple pairs of electrons can also be shared, resulting in double and triple bonds.
When one pair of electrons is shared between two atoms, a covalent bond is formed. This type of bond is a strong one that can be formed between two atoms of the same or different elements. The sharing of electrons fulfills each atom's need to complete its valence shell, or outer ring of electrons.
For example, hydrogen gas (H-H) is an instance of a single covalent bond where two atoms of hydrogen each share their solitary electron.
Further, it is important to note that more than one pair of electrons can be shared between a pair of atoms, leading to what we call double and triple bonds. For instance, in formaldehyde (CH₂O), a double bond forms as two pairs of electrons are shared between the carbon and oxygen atoms.
Learn more about Covalent Bond here:
https://brainly.com/question/33425898
#SPJ3
The percentage of water vapor present in the air compared to that required for saturation is the ____. a. mixing ratio b. relative humidity c. dew point d. absolute humidity
Answer:
B. Relative Humidity
An aqueous potassium carbonate solution is made by dissolving 6.35 moles of K 2 CO 3 in sufficient water so that the final volume of the solution is 4.30 L . Calculate the molarity of the K 2 CO 3 solution.
Answer:
The molarity of the solution is 1,48M
Explanation:
In chemistry, molarity, M, is an unit of concentration that represent the ratio between moles of solute and volume of solvent in liters.
In the problem, the solute is potassium carbonate, K₂CO₃, and the solvent is water.
There are 6.35moles of potassium carbonate and 4.30L of water. That means molarity is:
6,35mol / 4,30L = 1,48M
I hope it helps!
Objects with higher temperatures:________________.1. emit only shortwave radiation. 2. emit most of their energy in the form of longwave energy. 3. radiate less total energy than cooler objects radiate. 4. emit more shortwave radiation than cooler objects do.
Answer:
the awnser is 20dggrees
Explanation:
PLEASE HELP WILL GIVE BRAINLIEST
H2SO4 + Ba(OH)2à BaSO4 + H2O is an unbalanced chemical equation. What is the coefficient for water when this equation is balanced?
A.1
B.2
C.3
D.4
Answer:
2. Option B.
Explanation:
H₂SO₄ + Ba(OH)₂ → BaSO₄ + 2H₂O
You can count 2H in sulfuric acid and 2 H in the barium hyrdoxide, so the coefficient for water must be 2.
You will have 4 H on both sides of the reaction.
Try with the dissociations of each reactant
Sulfuric acid ⇒ H₂SO₄ → 2H⁺ + SO₄⁻²
Barium hydroxide ⇒ Ba(OH)₂ → Ba²⁺ + 2OH⁻
Sulfate anion bonds to barium cation to produce the salt, therefore the 2 protons will bond the 2 hydroxide in order to produce, 2 moles of H₂O
2H⁺ + 2OH⁻ → 2H₂O
Seawater density increases with increasing salinity and decreasing pressure. True or False
Answer:
FALSE
Explanation:
The density of seawater depends on certain factors such as-
Amount of salt present- The density of seawater is directly proportional to the salt concentration in the seawater. More is the amount of salt, more is the water density. Pressure- The seawater density increases with the increasing pressure. Pressure thus plays a significant role in controlling the density of seawater. The temperature of the seawater- The temperature also plays an important role, as both temperature and density of seawater are inversely proportional to each other.Thus, the above-given statement is False.
A certain amount of chlorine gas was placed inside a cylinder with a movable piston at one end. The initial volume was 3.00 L and the initial pressure of chlorine was 1.85 atm . The piston was pushed down to change the volume to 1.00 L. Calculate the final pressure of the gas if the temperature and number of moles of chlorine remain constant
Answer:
P₂ = 5.55 atm
Explanation:
Mathematically, Boyle's law can be stated as:
[tex]{\displaystyle P\propto {\frac {1}{V}}}[/tex]
Pressure is inversely proportional to the volume
[tex]{\displaystyle PV=k}[/tex] Pressure multiplied by volume equals some constant [tex]{\displaystyle k}[/tex]
where P is the pressure of the gas, V is the volume of the gas, and k is a constant.
The equation states that the product of pressure and volume is a constant for a given mass of confined gas and this holds as long as the temperature is constant. For comparing the same substance under two different sets of conditions, the law can be usefully expressed as:
[tex]{\displaystyle P_{1}V_{1}=P_{2}V_{2}[/tex]
The final pressure of a gas is calculated using Bolyes law formula
that is P1V1 =P2V2
Because the temperature and number of moles remained constant, we can use the formula
P₁V₁=P₂V₂
3.00 L * 1.85 atm = P₂ * 1.00 L
P₂ = 5.55 atm