Answer:
Theoretical yield=0.764 g.
Percent yield 42%.
Explanation:
Hello,
In this case the undergoing chemical reaction is shown on the attached picture. In such a way, starting by the given mass of 2-naphtol, one computes the theoretical yielded grams of 2-butoxynaphthalene as shown below, considering their 1 to 1 molar relationship:
[tex]m_{2-butoxynaphthalene}=0.55g2-naphtol*\frac{1mol2-naphtol}{144.17g2-naphtol}*\frac{1mol2-butoxynaphthalene}{1mol2-naphtol}*\frac{200.28g2-butoxynaphthalene}{1mol2-butoxynaphthalene}=0.764g2-butoxynaphthalene[/tex]
Moreover, the percent yield turns out:
[tex]Y=\frac{0.32g}{0.764g}*100\% =42\%[/tex]
Best regards.
Without the balanced chemical equation and molar masses, the theoretical yield of 2-butoxynaphthalene cannot be calculated. Normally, it involves stoichiometric calculations from the starting material. Percent yield is obtained by dividing actual yield by theoretical yield and multiplying by 100%.
Explanation:To calculate the theoretical yield and percent yield for the given reaction, we need to perform a few stoichiometric calculations. However, without the balanced chemical equation and the molar masses, we cannot calculate the theoretical yield for the specific reaction of 2-naphthol and 1-bromobutane to form 2-butoxynaphthalene. If we had the balanced equation, we would calculate the moles of 2-naphthol used, and using stoichiometry, find the moles of 2-butoxynaphthalene that could be formed. Multiplying by the molar mass would give us the theoretical yield in grams. To find percent yield, we would then divide the actual yield (0.32 g) by the theoretical yield and multiply by 100.
Generally speaking, percent yield is the ratio of the actual yield to the theoretical yield multiplied by 100%. It indicates the efficiency of a chemical reaction and can be decreased by incomplete reactions, side reactions, or product recovery losses.
A chemist adds 55.0mL of a ×1.710−5/mmolL mercury(II) iodide solution to a reaction flask. Calculate the micromoles of mercury(II) iodide the chemist has added to the flask. Be sure your answer has the correct number of significant digits.
Answer:
The answer is 0.017 μmol of mercury iodide
Explanation:
To know the micromoles we must use the following conversion, 1 mmol = 1000μmol. we use a rule of three for the calculation of micromoles:
1mmol------------------1000μmol
1.7x10^-5mmol------- Xμmol
Clearing the X, we have:
X μmol = (1.7x10^-5x1000)/1 = 0.017μmol
Insert the IF statement in cell I9 to determine if the % Down is greater than or equal to 20% Down Pmt Rate. If true, the PMI is 0. If false, the PMI is calculated by multiplying the Amount Financed by the PMI Rate divided by the # of Pmts Per Year. The function should be =IF(E9>=$B$7,0,D9*$B$6/$B$5).
To address a conditional situation in Excel, you would use the IF function. In this case, the asked function is =IF(E9>=$B$7, 0, D9*$B$6/$B$5), wherein a condition is evaluated and if true, returns 0, if false, conducts a specified calculation.
Explanation:The question asked is about using the IF statement in Excel, which falls under the Computers and Technology topic. Excel's IF function is used to create conditional statements, where different calculations can be performed depending on whether a particular condition is met.
For the given question, you are asked to insert the IF function in cell I9. The condition to test is if the value in cell E9 is greater than or equal to the value in cell B7. If this condition is true, the function will return 0. If the condition is not met, the function will execute a calculation: it multiplies the values in cells D9 and B6, then divides the result by the value in cell B5.
Your final function should look like this: =IF(E9>=$B$7,0,D9*$B$6/$B$5).
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In the laboratory, a general chemistry student measured the pH of a 0.329 M aqueous solution of benzoic acid, C6H5COOH to be 2.327. Use the information she obtained to determine the Ka for this acid. Ka(experiment) =
Answer:
The dissociation constant for the acid ( experimental ) is 1.45 lit/mol
Explanation:
The value of dissociation constant can be calculated as,
[tex]K_{a}[/tex] = C × ∝²
Where, C = concentration of the solution = 0.329M
∝ = Degree of dissociation
again , Degree of dissociation can be obtained form :
[tex]p_{H}[/tex] = C × ∝
∝ = [tex]\frac{p_{H} }{C}[/tex]
∝ = [tex]\frac{2.327}{0.329}[/tex] = 7.072
So, now [tex]K_{a}[/tex] = C × ∝²
= 0.329 ×( 7.072)²
= 1.45 lit/ mol
Answer:
The Ka = 6.74 * 10^-5
Explanation:
Step 1: Data given
Concentration of benzoic acid = 0.329 M
pH = 2.327
Step 2: Calculate the Ka
pH = -log (√([HA]*Ka))
2.327 = -log (√(0.329*Ka))
10 ^ - 2.327 = √(0.329*Ka))
0.0047098 = √(0.329*Ka))
2.218 * 10^-5 = 0.329 * Ka
Ka = 6.74 * 10^-5
The Ka = 6.74 * 10^-5
Methylamine, CH3NH2, is a weak base and one of several substances that give herring brine its pungent odor. In .100 M CH3NH2, only 6.4 percent of the base has undergone ionization. What are Kb and pKb of methylamine
Answer:
[tex]K_{b}[/tex] is 0.000438 and [tex]pK_{b}[/tex] is 3.36
Explanation:
Methylamine is a monoprotic base.
For a monoprotic base, [tex]K_{b}=\frac{ca^{2}}{(1-a)}[/tex]
where, c is concentration of base in molarity and a is it's degree ionization
Here [tex]a=\frac{6.4}{100}=0.064[/tex] and c = 0.100 M
So, [tex]K_{b}=\frac{(0.100)\times (0.064)^{2}}{(1-0.064)}=0.000438[/tex]
We know, [tex]pK_{b}=-logK_{b}[/tex]
Hence, [tex]pK_{b}=-log(0.000438)=3.36[/tex]
At a given temperature, 4.92 atm of Cl2 and 4.65 atm of Br2 are mixed and allowed to come to equilibrium. The equilibrium pressure of BrCl is found to be 1.597 atm. Calculate Kp for the reaction at this temperature. Cl2(g) + Br2(g) <=> 2 BrCl(g). Give answer to 2 decimal places.
Answer:
Kp = 0.16
Explanation:
Step 1: Data given
Initial pressure of Cl2 = 4.92 atm
Initial pressure of Br2 = 4.65 atm
The equilibrium pressure of BrCl is found to be 1.597 atm
Step 2: The balanced equation
Cl2(g) + Br2(g) ⇔ 2 BrCl(g
Step 3: The initial pressures
pCl2 = 4.92 atm
pBr2 = 4.65 atm
pBrCl = 0 atm
Step 4: The pressure at the equilibrium
For 1 mol Cl2 we need 1 mol Br2 to produce 2 moles BrCl
pCl2 = 4.92 - X atm
pBr2 = 4.65 - Xatm
pBrCl = 2X atm = 1.597 atm
X = 1.597/2 = 0.7985 atm
pCl2 = 4.92 - X atm = 4.92 - 0.7985 = 4.1215 atm
pBr2 = 4.65 - Xatm = 3.8515 atm
Step 5: Calculate Kp
Kp = (BrCl)² / (Cl2)*(Br2)
Kp = 1.597² / (4.1215*3.8515)
Kp = 0.16
Final answer:
To calculate Kp for the given reaction, start with the initial pressures of Cl2 and Br2, calculate the change in pressure due to the formation of BrCl, and apply these values in the Kp equation. The result is Kp = 0.084.
Explanation:
The student asked how to calculate Kp for the reaction Cl2(g) + Br2(g) ⇌ 2 BrCl(g) at a given temperature, given initial pressures for Cl2 and Br2, and the equilibrium pressure of BrCl. To solve for Kp, we utilize the change in concentration according to the reaction's stoichiometry and apply it to the equation for the equilibrium constant in terms of pressure (Kp).
Initial pressures: Cl2 = 4.92 atm, Br2 = 4.65 atm. At equilibrium, BrCl = 1.597 atm. The change in pressure for Cl2 and Br2 to form 2 BrCl is equal to the pressure of BrCl divided by 2, since the stoichiometry of the reaction dictates twice the amount of BrCl for each reactant consumed. Thus, the change (δ) is 1.597 atm / 2 = 0.7985 atm. Therefore, the pressures of Cl2 and Br2 at equilibrium are 4.92 - 0.7985 atm and 4.65 - 0.7985 atm, respectively.
To find Kp, the equation is Kp = (PBrCl)2 / (PCl2 × PBr2). Substituting the equilibrium pressures into this equation gives Kp = (1.5972) / ((4.92 - 0.7985) × (4.65 - 0.7985)). Solving this yields Kp = 0.084 (to two decimal places).
If a 32.4 gram sample of sodium sulfate (Na2SO4) reacts with a 65.3 gram sample of barium chloride (BaCl2) according to the reaction below: Na2SO4 (aq) + BaCl2 (aq) → BaSO4 (s) + 2NaCl (aq) What is the theoretical yield of barium sulfate (BaSO4) in grams?
Answer: The theoretical yield of barium sulfate is 50.9 grams
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
For sodium sulfate:Given mass of sodium sulfate = 32.4 g
Molar mass of sodium sulfate = 142 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of sodium sulfate}=\frac{32.4g}{142g/mol}=0.228mol[/tex]
For barium chloride:Given mass of barium chloride = 65.3 g
Molar mass of barium chloride = 208.23 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of barium chloride}=\frac{65.3g}{208.23g/mol}=0.314mol[/tex]
The chemical equation for the reaction of barium chloride and sodium sulfate follows:
[tex]Na_2SO_4+BaCl_2\rightarrow BaSO_4+2NaCl[/tex]
By Stoichiometry of the reaction:
1 mole of sodium sulfate reacts with 1 mole of barium chloride
So, 0.228 moles of sodium sulfate will react with = [tex]\frac{1}{1}\times 0.228=0.228mol[/tex] of barium chloride
As, given amount of barium chloride is more than the required amount. So, it is considered as an excess reagent.
Thus, sodium sulfate is considered as a limiting reagent because it limits the formation of product.
By Stoichiometry of the reaction:
1 mole of sodium sulfate produces 1 mole of barium sulfate.
So, 0.228 moles of sodium sulfate will produce = [tex]\frac{1}{1}\times 0.228=0.228moles[/tex] of barium sulfate
Now, calculating the mass of barium sulfate from equation 1, we get:
Molar mass of barium sulfate = 233.4 g/mol
Moles of barium sulfate = 0.228 moles
Putting values in equation 1, we get:
[tex]0.228mol=\frac{\text{Mass of barium sulfate}}{223.4g/mol}\\\\\text{Mass of barium sulfate}=(0.228mol\times 223.4g/mol)=50.9g[/tex]
Hence, the theoretical yield of barium sulfate is 50.9 grams
Two important indicators of stream pollution are high biological oxygen demand (BOD) and low pH. Of the more than 250 streams draining into a large lake, 30% have high BOD and 20% have low pH levels, with 10% having both characteristics.
Answer:
a) The Venn diagram is presented in the attached image to this answer.
b) Check Explanation.
c) 0.3333
d) 0.1429
e) 0.6
Explanation:
Let the probability of a lake having high BOD be P(B) = 30% = 0.3
Probability of a lake having low pH = P(P) = 20% = 0.2
Probability that a lake has high BOD and low pH = P(B n P) = 10% = 0.1
Then, probability that a lake has normal BOD = P(B') = 1 - P(B) = 1 - 0.3 = 0.7
Probability that a lake has normal pH = P(P') = 1 - P(P) = 1 - 0.2 = 0.8
Total probability = P(U) = 100% = 1
a) The Venn diagram is presented in the attached image to this answer.
b) Two events are independent if and only if, P(A|B) = P(A) or P(B|A) = P(B).
For this question,
P(B|P) = P(B n P)/P(P) = 0.1/0.2 = 0.5 ≠ P(B) (which is 0.3)
And P(P|B) = P(B n P)/P(B) = 0.1/0.3 = 0.333 ≠ P(P) (which is 0.2).
It is evident that the two events aren't independent of each other.
c) If a stream has high BOD, what is the probability it will also have low pH?
This probability is given as P(P|B) meaning that, the probability of a lake having low pH given that it has high BOD.
Mathematically, this conditional probability is given by
P(P|B) = P(B n P)/P(B) = 0.1/0.3 = (1/3) = 0.3333
d) If a stream has normal levels of BOD, what is the probability it will also have low pH.
This probability is given as P(P|B'); that is, the probability of a lake having low pH given that it has normal BOD.
Mathematically,
P(P|B') = P(B' n P)/P(B')
P(B') = 0.7 (already found above)
But P(B' n P) = ?
Mathematically,
P(B' n P) = P(P) - P(B n P) = 0.2 - 0.1 = 0.1
P(P|B') = 0.1/0.7 = 0.1429
e) What is the probability that a stream will not exhibit either pollution indicator, i.e., will have normal BOD and pH levels?
This is given as P(B' n P')
Mathematically, this represents the region in the Venn diagram outside of the circles representing P(B) and P(P) and it's given mathematically as,
P(B' n P') = P(U) - [P(B n P') + P(B' n P) + P(B n P)] = 1 - (0.2 + 0.1 + 0.1) = 1 - 0.4 = 0.6 or 60%
When the stream has high BOD the probability of low pH is 0.33 and 0.142 when it has normal BOD. 0.6 is the probability that a stream will exhibit neither indicator.
What is BOD?BOD is the biological oxidation demand, that tells about the dissolved oxygen amount in the water body. BOD along with pH are the indicator of pollution.
The Venn diagram is attached in the image below.
The two indicators, high BOD and low pH are dependent on each other. It can be shown as:
[tex]\rm P(A|B) = P(A) \;or \;P(B|A) = P(B)[/tex]
But,
[tex]\begin{aligned}\rm P(B|P) &= \rm \dfrac{P(B \;n \;P)}{P(P)} \\\\&= \dfrac{0.1}{0.2} \\\\&= 0.5 \neq \rm P(B)\end{aligned}[/tex]
And
[tex]\begin{aligned}\rm P(P|B) &=\rm \dfrac{P(B \;n \;P)}{P(B)} \\\\&= \dfrac{0.1}{0.3} \\\\&= 0.333 \neq \rm P(P) \end{aligned}[/tex]
Hence they are not independent of each other.
The probability of low pH at high BOD is given as P(P|B).
[tex]\begin{aligned}\rm P(P|B) &= \rm \dfrac{P(B \;n \;P)}{P(B)}\\\\ &= \dfrac{0.1}{0.3}\\\\&= 0.3333\end{aligned}[/tex]
Hence, 0.33 is the probability of low pH at high BOD.
The probability of low pH at normal BOD is given as P(P|B').
[tex]\begin{aligned}\rm P(P|B') &= \rm \dfrac{P(B' \;n\; P)}{P(B')}\\\\\rm P(P|B') &= \dfrac{0.1}{0.7} \\\\&= 0.1429\end{aligned}[/tex]
Hence, 0.1429 is the probability of low pH at normal BOD.
The probability that a stream will not exhibit any of the indicators is given by, P(B' n P').
[tex]\begin{aligned}\rm P(B' n P') &= \rm P(U) - [P(B n P') + P(B' n P) + P(B n P)]\\\\&= 1 - (0.2 + 0.1 + 0.1) \\\\&= 0.6\end{aligned}[/tex]
Hence, 0.6 is the probability that neither of the indicators will be expressed.
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Consider the reaction N2(g) + 2O2(g)2NO2(g) Using standard thermodynamic data at 298K, calculate the entropy change for the surroundings when 1.90 moles of N2(g) react at standard conditions. S°surroundings =
Final answer:
To calculate the entropy change for the surroundings during the reaction of N2(g) and O2(g) to form NO2(g), the standard enthalpy change of the reaction must be known. This value can be used with the equation ΔS° = -ΔH°/T to find the entropy change of the surroundings.
Explanation:
The student is asking to calculate the entropy change for the surroundings (ΔS°surroundings) when 1.90 moles of N2(g) react with O2(g) to form NO2(g) according to the reaction N2(g) + 2O2(g) → 2NO2(g) at standard conditions of 298 K.
To find this, we'll first need the standard enthalpy change (ΔH°) for the reaction, which can be obtained from standard thermodynamic tables. We then apply the equation ΔS° = -ΔH°/T, which relates the entropy change of the surroundings to the enthalpy change of the system at a constant temperature (T).
Given that the standard enthalpy change for the formation of NO2(g) is 33.2 kJ/mol, and the reaction produces 2 moles of NO2 for 1 mole of N2, the standard enthalpy change for the reaction when 1.90 moles of N2 react is (1.90 moles * 33.2 kJ/mol * 2). We'll convert kJ to J by multiplying by 1,000 and then calculate ΔS°surroundings.
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Final answer:
The standard entropy change for the reaction N2(g) + 2O2(g) → 2NO2(g) at 298K can be calculated using the equation: ΔS° = 2∙S°(NO2) - [S°(N2) + 2∙S°(O2)]. The entropy change is -198.3 J/mol K.
Explanation:
The standard entropy change for the reaction N2(g) + 2O2(g) → 2NO2(g) at 298K can be calculated using the equation: ΔS° = 2∙S°(NO2) - [S°(N2) + 2∙S°(O2)].
Using the standard entropy values at 298K from the reference table, we can substitute the values and calculate the entropy change:
ΔS° = 2∙192.5 - [191.5 + 2∙130.6]
ΔS° = -198.3 J/mol K
Click in the answer box to activate the palette. List the following molecules in order of increasing dipole moment: H2O, CBr4, H2S, HF, NH3, CO2 < < < < Electronegativities H 2.1 C 2.5 N 3.0 O 3.5 F 4.0 S 2.5 Br 2.8
Answer:
HF > H2O > NH3 > H2S > CBr4=CO2=0
Explanation:
Dipole moment is a vector quantity. Its a measure of polarity of a bond in a molecule and also a meaure of separation of positive and negative charge in a system.It occurs due to electronegativity difference between the atoms in a molecule.
In order for a molecule to have dipole moment, a molecule must exhibit high electronegativity difference and the shape of the moloecule must be asymmetry
HF has the highest electronegativity difference among all the molecules listed above hence its dipole moment is the greatest.
[tex]H_{2}O[/tex] has a bent structure. There are two O-H bonds hence more charge dipoles. The dipole moment is less than HF molecule because of the net dipole moments of two O-H bonds.
[tex]CO_{2}[/tex] is a linear molecule.However it has polar bonds.But because of the shape of the molecule, the two C-O bond dipoles cancel out each other hence the overall dipole moment will be zero.
Similarly in [tex]CBr_{4}[/tex], ,since the molecule is symmetry, the bond dipole cancels each other out hence the overall dipole moment will be zero.
The increasing order of the dipole moment will be:
[tex]\rm CO_2[/tex] < [tex]\rm CBr_4[/tex] < [tex]\rm H_2S[/tex] < [tex]\rm NH_3[/tex] < [tex]\rm H_2O[/tex] < HF.
Dipole moment can be described as the measure of the polarity of the molecule. The higher the electronegativity difference, the more polar the bond.
In the given molecules,
HF: The electronegativity difference is 1.9.[tex]\rm H_2O[/tex] : The molecule is bend, and the difference in electronegativity is 1.4.[tex]\rm CBr_4[/tex] : The molecule is symmetrical, which cancels the dipole. The net dipole is zero.[tex]\rm H_2S[/tex] : The electronegativity difference is 0.4.[tex]\rm NH_3[/tex] : The electronegativity difference is 0.9.[tex]\rm CO_2[/tex]: The molecule has a symmetrical arrangement. Thus the net dipole of the molecule is 0.The increasing order of the dipole moment will be:
[tex]\rm CO_2[/tex] < [tex]\rm CBr_4[/tex] < [tex]\rm H_2S[/tex] < [tex]\rm NH_3[/tex] < [tex]\rm H_2O[/tex] < HF.
The molecule with the highest dipole moment is HF.
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For this heterogeneous system 2 A ( aq ) + 3 B ( g ) + C ( l ) − ⇀ ↽ − 2 D ( s ) + 3 E ( g ) the concentrations and pressures at equilibrium are [ A ] = 9.68 × 10 − 2 M , P B = 9.54 × 10 3 Pa , [ C ] = 14.64 M , [ D ] = 10.11 M , and P E = 9.56 × 10 4 torr . Calculate the thermodynamic equilibrium constant, K.
Answer:
[tex]2.55*10^{11[/tex]
Explanation:
Equation for the heterogeneous system is given as:
[tex]2A_{(aq)} + 3 B_{(g)} + C_{(l)}[/tex] ⇄ [tex]2D_{(s)}[/tex] [tex]+[/tex] [tex]3E_{(g)}[/tex]
The concentrations and pressures at equilibrium are:
[tex][A] = 9.68*10^{-2}M[/tex]
[tex]P_B = 9.54*10^3Pa[/tex]
[tex][C]=14.64M[/tex]
[tex][D]=10.11M[/tex]
[tex]P_E=9.56*10^4torr[/tex]
If we convert both pressure into bar; we have:
[tex]P_B = 9.54*10^3Pa[/tex]
[tex]P_B = (9.54*10^3)*\frac{1}{10^5} bar[/tex]
[tex]P_B=9.54*10^{-2}bar[/tex]
[tex]P_E=9.56*10^4torr[/tex]
1 torr = 0.001333 bar
[tex]9.54*10^4 *0.001333 = 127.5 bar[/tex]
[tex]K=\frac{[P_E]^3}{[A]^2[P_B]^3}[/tex]
[tex]K=\frac{(127.5)^3}{(9.68*10^{-2})^2(9.54*10^{-2})^3}[/tex]
[tex]K=2.55*10^{11[/tex]
how many moles of solute are in 300 mL of 1.5 M CaCl2? How many grams fo CaCl2 is this?
Answer:
1. 0.45 mole
2. 49.95g
Explanation:
The following were obtained from the question:
Volume of solution = 300mL = 300/1000 = 0.3L
Molarity = 1.5 M
Mole of CaCl2 =?
1. We can obtain the mole of the solute as follow:
Molarity = mole of solute /Volume of solution
1.5 = mole of solute/0.3
Mole of solute = 1.5 x 0.3
Mole of solute = 0.45 mole
2. The grams in 0.45 mole of CaCl2 can be obtained as follow:
Molar Mass of CaCl2 = 40 + (35.5 x 2) = 40 + 71 = 111g/mol
Mole of CaCl2 = 0.45 mole
Mass of CaCl2 =?
Mass = number of mole x molar Mass
Mass of CaCl2 = 0.45 x 111
Mass of CaCl2 = 49.95g
Answer:
We have 0.45 moles CaCl2 in this 1.5 M solution
This 49.9 grams of CaCl2
Explanation:
Step 1: data given
Volume of the CaCl2 solution = 300 mL = 0.300 L
Molarity of the CaCl2 solution = 1.5 M
Molar mass CaCl2 = 110.98 g/mol
Step 2: Calculate number of moles in the solution
Moles CaCl2 = molarity solution * volume of solution
Moles CaCl2 = 1.5 M * 0.300 L
Moles CaCl2 = 0.45 moles
Step 3: Calculate mass CaCl2
Mass CaCl2 = moles CaCl2 * molar mass CaCl2
Mass CaCl2 = 0.45 moles * 110.98 g/mol
Mass CaCl2 = 49.9 grams CaCl2
We have 0.45 moles CaCl2 in this 1.5 M solution
This 49.9 grams of CaCl2
Select the statements that are correct with respect to waste disposal in the Electrochemical Cells Experiment. (Select all that apply.)
a. Dilute copper and ascorbic acid solutions should be disposed of in the waste container in the hood.
b. Rinsings from the half-cell module can be flushed down the sink.
c. Metal and graphite electrodes should be rinsed with water, dried, and returned to their positions on the lab bench.
d. The contents of the half-cell module should be disposed of in the waste container in the hood.
e. No waste will be generated during this experiment.
f. The electrodes should be discarded in the proper jar.
Answer:A. Dilute copper and ascorbic acid solutions should be disposed of in the waste container in the hood.
C. Metal and graphite electrodes should be rinsed with water, dried, and returned to their positions on the lab bench.
D. The contents of the half-cell module should be disposed of in the waste container in the hood.
Explanation: An electrochemical cell is a cell that has the capability of producing Electric energy from chemical reaction (voltaic cells) or using Electric energy to make chemical reactions to take place(electrolytic cell). For a proper or effective waste disposal in an electrochemical cell the following options are correct.
Dilute copper and ascorbic acid solutions should be disposed of in the waste container in the hood.
Metal and graphite electrodes should be rinsed with water, dried, and returned to their positions on the lab bench.
The contents of the half-cell module should be disposed of in the waste container in the hood.
In the Electrochemical Cells Experiment, the correct statements regarding waste disposal include disposing copper and ascorbic acid solutions in the waste container, flushing rinsings from the half-cell module down the sink, and rinsing and drying the electrodes.
Explanation:The correct statements with respect to waste disposal in the Electrochemical Cells Experiment are:
Dilute copper and ascorbic acid solutions should be disposed of in the waste container in the hood.Rinsings from the half-cell module can be flushed down the sink.Metal and graphite electrodes should be rinsed with water, dried, and returned to their positions on the lab bench.The contents of the half-cell module should be disposed of in the waste container in the hood.No waste will be generated during this experiment.The electrodes should be discarded in the proper jar.A mixture of 0.438 M H2, 0.444 M I2 , and 0.895 M HI is enclosed in a vessel and heated to 430 °C. H2 (g) + I2 (g) <-----> 2 HI (g) Kc = 54.3 at 430∘C Calculate the equilibrium concentrations of each gas at 430∘C.
Answer:
[H₂] = 0.178 M
[I₂] = 0.184 M
[HI] = 1.415 M
Explanation:
For the equilibrium:
H₂(g) + I₂(g) ⇄ 2 HI(g)
the equilibrium constant is given by the equation:
Kc = [ HI]² / [H₂][I₂]
Lets use first the reaction quotient which has the same expression as the equilibrium constant to predict the direction the reaction will take, i.e towards reactants or product side.
Q =( 0.895)²/(0.438)(0.444) = 4.12
Q is less than Kc so the reaction will favor the product side.
We can set up the following table to account for all the species at equilibrium:
H₂ I₂ HI
initial 0.438 0.444 0.895
change -x -x +2x
equilibrium 0.438 - x 0.444 - x 0.895 + 2x
Now we are in position to express these concentrations in terms of the equilibrium conctant, Kc
54.3 = (0.895 + 2x)² / (0.438 -x)(0.444 - x)
performing the calculatiopns will result in a quadratic equation:
0.801 + 3.580x +4x² = (0.194 - 0.882x + x²)x 54.3
Upon rearrangement and some algebra, we have
0.801 + 3.580 x + 4x² = 10.534 - 47.893x + 54.3 x²
0 = 9.733 - 51.473 x + 54.3 x²
This equation has two roots X₁ = 0.687 and X₂ = 0.26
The first is physically impossible since it will imply that more 0.687 will make the quantity at equilibrium for both H₂ and I₂ negative.
Therefore the concentrations at equilibrium of each gas are:
[H₂] = (0.438 - 0.260) = 0.178 M
[I₂] = (0.444 - 0.260) M = 0.184 M
[HI] = [0.895 + 2x(0.260)] M = 1.415 M
Note if we plug these values into the equilibrium expression we get 61 which is due to the rounding errors propagating in the quadratic equation.
The equilibrium concentrations of H2, I2, and HI at 430 °C are calculated using an expression derived from the reaction quotient equation, plugged into the Kc equation, which is then solved for 'x'. The solutions found are the changes in molarities which applied to the initial molarities give the equilibrium concentrations
Explanation:Let's denote the change in molarity of H2, I2, and HI as 'x'. At equilibrium, the molarities of H2, I2, and HI will be 0.438+x, 0.444+x, and 0.895-2x respectively. We know the equilibrium constant, Kc = 54.3. Thus, (0.895-2x)2/(0.438+x)(0.444+x) = 54.3. This is a quadratic equation in 'x' and needs to be solved to get the value of 'x'.
After finding 'x', put this value back into the equilibrium concentrations of the gases, i.e., 0.438+x for H2, 0.444+x for I2, and 0.895-2x for HI. These will give you the equilibrium concentrations of the gases at 430 °C.
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In light of the nuclear model for the atom, which statement is true?
A) For a given element, the size of an isotope with more neutrons is larger than one with fewer neutrons.
B) For a given element, the size of an atom is the same for all of the element’s isotopes.
The true statement for nuclear model for the atom is B: For a given element, the size of an atom is the same for all of the element’s isotopes is
Explanation:
The isotopes are the atoms of an element that have different number of neutrons in their nuclei but same number of electrons.
The number of protons remains the same in isotopes.
the atomic mass of the isotope differ because the atomic mass is number of proton+ number of neutrons.
The atomic number remains the same since number of protons equals the number of protons.
The atomic radii does not change because the arrangement or number of electrons do not differ among the isotopes. Since there is no change in atomic radii the size remains same in isotopes of an element. Although the size of nucleus increases due to more protons.
The correct option is B). The true statement is For a given element, the size of an atom is the same for all of the element’s isotopes.
In the nuclear model of the atom, the size of an atom is primarily determined by the number of protons in the nucleus, which is the same for all isotopes of a given element. This is because the number of protons determines the atomic number, and thus the number of electrons in a neutral atom.
Isotopes of an element have the same number of protons but different numbers of neutrons. While the addition of neutrons does increase the mass of the atom, it does not significantly affect the size of the atom. The electron cloud is attracted to the positively charged protons in the nucleus, and since the number of protons remains constant for all isotopes of an element, the size of the electron cloud, and therefore the atomic radius, remains relatively constant.
The presence of additional neutrons can have a very slight effect on the atomic radius due to the increased mass of the nucleus, which might lead to a slightly stronger attraction between the nucleus and the electrons.
A sucrose solution is prepared to a final concentration of 0.210 MM . Convert this value into terms of g/Lg/L, molality, and mass %%. (Use the following values: molecular weight MWsucroseMWsucrose = 342.296 g/molg/mol ; density rhosol′nrhosol′n = 1.02 g/mLg/mL ; and mass of water, mwatmwat = 948.1 gg ). Note that the mass of solute is included in the density of the solution.
Answer:
1) 71.9 g/L
2) 0.221 m olal
3) 7.05% by mass
Explanation:
Step 1: Data given
Concentration of sucrose = 0.210 M
Molar weight of sucrose = 342.3 g/mol
Density of solution = 1.02 g/mL
Mass of water = 948.1 grams
Step 2: Convert this value into terms of g/L
(0.210 mol/L) * (342.3 g/mol) = 71.9 g/L
Calculate the molality
Step 1: Calculate mass water
Suppose we have a volume of 1.00L
Mass of the solution = 1000 mL * 1.02 g/mL = 1020 g solution
We know that there are 71.9 g of solute in a liter of solution from the first calculation. This means
(1020 grams solution) - (71.9 g solute) = 948.1 g = 0.9481 kg water
Step 2: Calculate molality
Molality = moles sucrose / mass water
(0.210 mol) / (0.9481 kg) = 0.221 mol/kg = 0.221 m olal
Mass %
% MAss = (mass solute / mass solution)*100%
(71.9 g) / (1020 g) *100% = 7.05% by mass
Ammonia will decompose into nitrogen and hydrogen at high temperature. An industrial chemist studying this reaction fills a 7.50 l tank with 29.0 mol of ammonia gas at 35.0 °C. She then raises the temperature, and when the mixture has come to equilibrium measures the amount of nitrogen gas to be 13.0 mol.
Calculate the concentration equilibrium constant for the decomposition of ammonia at the final temperature of the mixture. Round your answer to significant digits.
Answer: The equilibrium constant for the reaction is 2.47
Explanation:
We are given:
Initial moles of ammonia gas = 29.0 moles
Equilibrium moles of nitrogen gas = 13.0 moles
Volume of the tank = 7.50 L
Molarity is calculated by using the formula:
[tex]\text{Molarity}=\frac{\text{Number of moles}}{\text{Volume of tank}}[/tex]
[tex]\text{Initial molarity of ammonia}=\frac{29.0}{7.50}=3.87M[/tex]
[tex]\text{Equilibrium molarity of nitrogen gas}=\frac{13.0}{7.50}=1.73M[/tex]
The chemical equation for the decomposition of ammonia follows:
[tex]2NH_3\rightleftharpoons N_2+3H_2[/tex]
Initial: 3.87
At eqllm: 3.87-2x x 3x
Evaluating the value of 'x'
[tex]\Rightarrow 3x=1.73\\\\x=\frac{1.73}{3}=0.577[/tex]
So, equilibrium concentration of ammonia = (3.87 - 2x) = [3.87 - 2(0.577)] = 2.716 M
Equilibrium concentration of nitrogen gas = x = 0.577 M
The expression of [tex]K_{eq}[/tex] for above equation follows:
[tex]K_{eq}=\frac{[N_2][H_2]^3}{[NH_3]^2}[/tex]
Putting values in above equation, we get:
[tex]K_{eq}=\frac{(2.716)^2}{0.577\times (1.73)^3}\\\\K_{eq}=2.47[/tex]
Hence, the equilibrium constant for the reaction is 2.47
Acetic acid, ethanol, acetaldehyde and ethane form a series of 2-carbon molecules which differ in their extent of oxidation. Convert ethanol to the next more reduced form in that ordered series. HelpMarvin JS
Explanation:
Ethanol can be oxidized to ethanal or acetaldehyde which is further oxidized to acid that is acetic acid.
[tex]CH_3CH_2OH[/tex]→ [tex]CH_3CHO[/tex] [oxidation by loss of hydrogen]
An oxidizing agent potassium dichromate(VI) solution is used to remove the hydrogen from the ethanol. An oxidizing agent used along with dilute sulphuric acid for acidification.Acetaldehyde can also be reduced back to ethanol again by adding hydrogen to it by using a reducing agent that is sodium tetrahydro borate, NaBH4.
The oxidation of aldehydes to carboxylic acids can be done by the two-step process. In the first step, one molecule of water is added in the presence of a catalyst that is acidic. There is a generation of a hydrate. (geminal 1,1-diol).[tex]CH_3CHO[/tex] → [tex]CH_3CH_2COOH[/tex] [reduction by the gain of electrons]
Here, the oxidizing agent used is[tex]Cr_3O[/tex] in the presence of acetone.
To convert ethanol to the next more reduced form in the series, it will form an aldehyde called acetaldehyde.
Explanation:To convert ethanol to the next more reduced form in the series, we need to consider the oxidation level of the molecules. Ethanol is an alcohol with the -OH group bonded to a carbon atom attached to two other carbon atoms, which means it will form an aldehyde upon oxidation. Acetaldehyde is the next more reduced form in the series. Acetaldehyde has a carbonyl group (C=O) instead of an -OH group.
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Atmospheric pressure decreases as altitude increases. In other words, there is more air pushing down on you at sea level, and there is less air pressure pushing down on you when you are on a mountain.If hexane (C6H14), octane (C8H18), and octanol (C8H17OH) are heated evenly at different altitudes, rank them according to the order in which you would expect them to begin boiling.
Explanation:
Boiling point is the temperature at which vapor pressure of a liquid becomes equal to the atmospheric pressure.
So, more is the number of carbon atoms present in a compound that are linearly attached to each other more will be its boiling point. This is because then there are more intermolecular forces present in it and also it occupies more surface area.
Hence, in order to break these intermolecular forces more heat is required. As a result, boiling point of the compound increases.
Therefore, we can conclude that given compounds are ranked according to the increasing order in which you would expect them to begin boiling as follows.
Hexane at high altitude < Octane at high altitude < Octane at sea level < Octanol at sea level
Aqueous hydrochloric acid reacts with solid sodium hydroxide to produce aqueous sodium chloride and liquid water what is the terorectical yield of water formed from the reaction of 3.3 g of hydrocloric acid and 6.6g of sodium hydroxide?
Answer:
1.63 g of H₂O is the theoretical yield
Explanation:
We determine the reactants for the reaction:
HCl, NaOH
We determine the products for the reaction:
H₂O, NaCl
The equation for this neutralization reaction is:
HCl (aq) + NaOH(aq) → NaCl(aq) + H₂O(l)
We use both masses, from both reactants to determine the limiting.
First, we convert the mass to moles.
3.3 g . 1mol / 36.45 g = 0.090 moles of HCl
6.6 g . 1mol / 40 g = 0.165 moles of NaOH
Ratio is 1:1, so for 0.165 moles of hydroxide I need the same amount of acid. I have 0.090 HCl so the acid is the limiting reagent.
Let's work with stoichiometry. Ratio is 1:1, again.
1 mol of acid can produce 1 mol of water
Therefore, 0.090 moles of acid must produce 0.090 moles of H₂O
We convert the moles to mass, to define the theoretical yield
0.090 mol . 18g / 1 mol = 1.63 g
Answer:
The theoretical yield of H2O is 1.63 grams
Explanation:
Step 1: Data given
Mass of hydrochloric acid = 3.3 grams
Mass of sodium hydroxide = 6.6 grams
Molar mass hydrochloric acid (HCl) = 36.46 g/mol
Molar mass sodium hydroxide (NaOH) = 40.0 g/mol
Step 2: The balanced equation
HCl + NaOH → NaCl + H2O
Step 3: Calculate moles
Moles = mass / molar mass
Moles HCl = 3.3 grams / 36.46 g/mol
Moles HCl = 0.0905 moles
Moles NaOH = 6.6 grams / 40.0 g/mol
Moles NaOH = 0.165 moles
Step 4: Calculate the limiting reactant
HCl is the limiting reactant. There will react 0.0905 moles. NaOH is in excess. There will react 0.0905 moles moles. There will remain 0.165 - 0.0905 = 0.0745 moles
Step 5: Calculate moles H2O
For 1 mol HCl we need 1 mol NaOH to produce 1 mol NaCl and 1 mol H2O
For 0.0905 moles HCl we'll have 0.0905 moles H2O
Step 6: Calculate mass H2O
Mass H2O = moles * molar mass
Mass H2O = 0.0905 * 18.02 g/mol
Mass H2O = 1.63 grams
The theoretical yield of H2O is 1.63 grams
Using your data above, draw conclusions about the d-splitting for each ligand (H2O, en, phen). Order the complexes from least to greatest d-splitting, and discuss the reason for your ordering.
Answer:
H2O<en<phen
Explanation:
The degree of d- splitting is observed from the intensity of colour. The order of d splitting from least to greatest is H2O<en<phen. Phen shows the greatest d-splitting. The degree of splitting of d- orbitals by ligands depends on their relative positions in the spectrochemical series. The spectrochemical series is an experimentally determined series. The series separates the ligands into strong field and weak field ligands. Strong field ligands are found towards the end of the series. Strong field ligands such as en and phen can participate in metal to ligand or ligand to metal pi-bonding. Hence they cause more d-splitting. Ethylendiamine and phenanthroline occur towards the end of the spectrochemical series hence the higher order of d-splitting.
The d-splitting for each ligand is as follows:
H2O (weak field ligand): smallest d-splitting
en (stronger field ligand): medium d-splitting
phen (strongest field ligand): largest d-splitting
The complexes from least to greatest d-splitting are as follows:
[Co(H2O)6]3+
[Co(en)3]3+
[Co(phen)3]3+
The reason for this ordering is that stronger field ligands cause a larger d-splitting. This is because stronger field ligands interact more strongly with the metal's d orbitals, which splits the d orbitals into two sets of orbitals with different energies.
The d-splitting of a transition metal complex is the energy difference between the two sets of d orbitals that are split by the ligand field. The magnitude of the d-splitting depends on the strength of the ligand field. Stronger field ligands cause a larger d-splitting.
The following table shows the spectrochemical series of ligands, which is a ranking of ligands from weakest to strongest field:
| Ligand | Spectrochemical series |
|---|---|---|
| H2O | Weak field |
| en | Medium field |
| phen | Strong field |
Based on the spectrochemical series, we can predict that the d-splitting for each ligand is as follows:
H2O (weak field ligand): smallest d-splitting
en (stronger field ligand): medium d-splitting
phen (strongest field ligand): largest d-splitting
The following table shows the expected d-splitting of the [Co(H2O)6]3+, [Co(en)3]3+, and [Co(phen)3]3+ complexes:
Complex Ligand D-splitting
[Co(H2O)6]3+ H2O Smallest
[Co(en)3]3+ en Medium
[Co(phen)3]3+ phen Largest
The d-splitting of a transition metal complex affects the color of the complex. Complexes with a larger d-splitting absorb higher energy light, which is in the visible region of the spectrum. This is why complexes with strong field ligands tend to be colored.
The following table shows the observed colors of the [Co(H2O)6]3+, [Co(en)3]3+, and [Co(phen)3]3+ complexes:
Complex Ligand Color
[Co(H2O)6]3+ H2O Purple
[Co(en)3]3+ en Purple-pink
[Co(phen)3]3+ phen Pink
The observed colors of the complexes are consistent with the predicted d-splitting. The [Co(phen)3]3+ complex has the largest d-splitting and absorbs the highest energy light, which is why it is pink. The [Co(H2O)6]3+ complex has the smallest d-splitting and absorbs the lowest energy light, which is why it is purple.
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When a diprotic acid, , is titrated with , the protons on the diprotic acid are generally removed one at a time, resulting in a pH curve that has the following generic shape: Notice that the plot has essentially two titration curves. If the first equivalence point occurs at 100.0 mL added, what volume of added corresponds to the second equivalence point? Volume = mL For the following volumes of added, list the major species present after the reacts completely.
In a titration involving a diprotic acid, the equivalence points occur when the acid has lost its protons. If the first equivalence point occurs at 100 mL, the second should occur at 200 mL. resultant species in the solution will vary based on the volume of NaOH added.
Explanation:A diprotic acid has two protons to donate in a reaction. During titration, protons are removed one at a time, thus presenting two titration curves or equivalence points. If the first equivalence point occurs at 100.0 mL, the second equivalence point typically occurs at twice that volume because the second proton is just as readily removed as the first. Therefore, the second equivalence point will be at 200.0 mL.
Different volumes of added NaOH will result in different major species present. For example, before the equivalence point is reached (0 mL < V< 25 mL), the pH increases gradually as the diprotic acid reacts with the added NaOH to form its conjugate base. At the equivalence point (V = 25 mL), pH increases abruptly as the reaction transitions from acidic to either neutral or basic, depending on whether the diprotic acid is strong or weak, respectively. After the equivalence point (V > 25 mL), the pH is determined by the amount of added NaOH.
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Arrange the following aqueous solutions, all at 25 ∘C, in order of decreasing acidity. Rank from most acidic to most basic. To rank items as equivalent, overlap them.
Answer:
Rank from most acidic to most basic is
0.0023 M HClpH = 5.45 and pOH = 8.550.0018 M KOHExplanation:
This question is missing options.
Options are
pOH = 8.55 pH= 5.45 0.0023 M HCl 0.0018 M KOHTo rank these solutions first calculate either pH or pOH of these solutions.
We will use pH as an indicator to rank these.
Relation between pH and pOH is
pH + pOH = 14 ................... Eq (A)
For pOH = 8.55
use equation A
pH + 8.55 = 14
pH = 5.45
For pH = 5.45
pH = 5.45
For 0.0023 M HCl
HCl is a strong acid. It will ionize 100% in aqueous solution and produce Hydronium Ion. Formula to calculate pH of 0.0023 M HCl is,
pH = - log (Molarity)
pH = - log (0.0023)
pH = - (-2.64)
pH = 2.64
For 0.0018 M KOH
KOH is a base. It will produce Hydroxide Ion in aqueous solution. First calculate pOH and convert it into pH.
pOH = - log (Molarity)
pOH = - log (0.0018)
pOH = 2.74
use equation A
pH + 2.74 = 14
pH = 11.26
Lower the pH more acidic the solution is. Rank from most acidic to most basic is
0.0023 M HClpH = 5.45 and pOH = 8.550.0018 M KOH
The solutions, arranged from most acidic to most basic, are H₂SO₄, HCl, NH₄NO₃, NaCl, NaOH, and NaCN.
Explanation:The arrangement of the given solutions in order of decreasing acidity is as follows:
H₂SO₄ (Strong acid)HCl (Strong acid)NH₄NO₃ (Neutral salt)NaCl (Neutral salt)NaOH (Strong base)NaCN (Weak base)Strong acids completely dissociate in water, producing a large number of hydronium ions (H₃O⁺) and making the solution highly acidic. Neutral salts, such as NH₄NO₃ and NaCl, do not affect the pH of the solution. Strong bases, like NaOH, ionize completely and produce a high concentration of hydroxide ions (OH⁻), resulting in a basic solution. Weak bases, such as NaCN, only partially ionize, resulting in a lower concentration of OH⁻ ions and a slightly basic solution.
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The complete question is here:
Arrange the following aqueous solutions, all at 25 ∘C, in order of decreasing acidity. Rank from most acidic to most basic. To rank items as equivalent, overlap them.
H₂SO₄
HCl
NH₄NO₃
NaCl
NaOH
NaCN
Quantum numbers arise naturally from the mathematics used to describe the possible states of an electron in an atom. The four quantum numbers, the principal quantum number (n), the angular momentum quantum number (????), the magnetic quantum number (m????), and the spin quantum number (ms) have strict rules which govern the possible values. Identify all allowable combinations of quantum numbers for an electron.
Select all that apply.
a) n= 3 l= -2 ml=-1 ms= +1/2
b) n=3 l= 2 ml= -1 ms= -1/2
c) n= 4 l=4 ml=-1 ms= +1/2
d) n=2 l=1 ml=-1 ms=1
e) n=4 l=1 ml=2 ms=-1/2
f) n=5 l=4 ml=4 ms=+1/2
Answer:
a), b), c) & f)
Explanation:
d) does not apply because Ms value can be either +½ or -½
e) does not apply because Ml - values range from -l to +l, hence l= 2 doesn't exist when l= 1
The four quantum numbers that govern the possible states of an electron in an atom are the principal quantum number (n), the angular momentum quantum number (l), the magnetic quantum number (ml), and the spin quantum number (ms). Allowable combinations of quantum numbers follow specific rules.
Explanation:The four quantum numbers that govern the possible states of an electron in an atom are the principal quantum number (n), the angular momentum quantum number (l), the magnetic quantum number (ml), and the spin quantum number (ms).
Allowable combinations of quantum numbers for an electron can be determined according to the following rules:
The principal quantum number (n) can have values of 1, 2, 3, etc.The angular momentum quantum number (l) can have values from 0 to (n - 1).The magnetic quantum number (ml) can have values from -l to +l, including zero.The spin quantum number (ms) can have values of +1/2 or -1/2.A solution contains 4.08 g of chloroform (CHCl3) and 9.29 g of acetone (CH3COCH3). The vapor pressures at 35 ∘C of pure chloroform and pure acetone are 295 torr and 332 torr, respectively. Assuming ideal behavior, calculate the vapor pressures of each of the components and the total vapor pressure above the solution.
The vapor pressures of chloroform and acetone in the solution are 52.02 torr and 273.50 torr, respectively, and the total vapor pressure above the solution is 325.52 torr.
Explanation:To calculate the vapor pressures of chloroform and acetone above the solution, we should make use of Raoult's law. According to Raoult's law, the partial pressure of each component of a mixture is the product of the vapor pressure of the pure component and its mole fraction in the mixture.
First, calculate the mole fractions of each substance. The molar mass of chloroform (CHCl3) is about 119.38 g/mol, and the molar mass of acetone (CH3COCH3) is about 58.08 g/mol. Therefore, the mole fractions of chloroform and acetone are 4.08 g CHCl3 * (1 mol / 119.38 g) = 0.0342 mol and 9.29 g CH3COCH3 * (1 mol / 58.08 g) = 0.1599 mol, respectively. The total moles are 0.0342 mol + 0.1599 mol = 0.1941 mol, so the mole fraction of chloroform is 0.0342/0.1941 = 0.176 and that of acetone is 0.1599/0.1941 = 0.824.
Next, apply Raoult's Law to find the partial pressure of each component in the mixture. The vapor pressure of chloroform is 0.176 * 295 torr = 52.02 torr, and the vapor pressure of acetone is 0.824 * 332 torr = 273.50 torr.
The total vapor pressure above the solution is the sum of the vapor pressures of chloroform and acetone, that is, 52.02 torr + 273.50 torr = 325.52 torr.
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he rate constant for this zero‑order reaction is 0.0130 M ⋅ s − 1 at 300 ∘ C. A ⟶ products How long (in seconds) would it take for the concentration of A to decrease from 0.890 M to 0.280 M?
Answer:
188 s
Explanation:
We are told the reaction is second order respect to A so we know the expression for the rate law is
rate = - Δ[A]/Δt = k[A]²
where the symbol Δ stands for change, [A] is the concentration of A, and k is the rate constant.
The integrated rate law for this equation from calculus is
1 / [A]t = kt + 1/[A]₀
where [A]t is the concentration of A at time t, k is the rate constant, and [A]₀ is the initial concentration.
Since we have all the information required to solve this equation lets plug our values
1 / 0.280= 0.0130x t + 1 / 0.890
( 1 / 0.280 - 1 / 0.890)M⁻¹ = 0.0130 M⁻¹ ·s⁻¹t
t = 188 s
If 50.0 g of N2O4 is introduced into an empty 2.12 L container, what are the partial pressures of NO2 and N2O4 after equilibrium has been achieved at 45∘C?
Answer:
p(N2O4) = 0.318 atm
p(NO2) = 7.17 atm
Explanation:
Kc for the reaction N2O4 <=> 2NO2 is 0.619 at 45 degrees C If 50.0g of N2O4 is introduced into an empty 2.10L container, what are the partial pressures of NO2 and N2O4 after equilibrium has been achieved at 45 degrees C?
Step 1: Data given
Kc = 0.619
Temperature = 45.0 °C
Mass of N2O4 = 50.0 grams
Volume = 2.10 L
Molar mass N2O4 = 92.01 g/mol
Step 2: The balanced equation
N2O4 ⇔ 2NO2
Step 3: Calculate moles N2O4
Moles N2O4 = 50.0 grams / 92.01 g/mol
Moles N2O4 = 0.543 moles
Step 4: The initial concentration
[N2O4] = 0.543 moles/2.10 L = 0.259 M
[NO2]= 0 M
Step 5: Calculate concentration at the equilibrium
For 1 mol N2O4 we'll have 2 moles NO2
[N2O4] = (0.259 -x)M
[NO2]= 2x
Step 6: Calculate Kc
Kc = 0.619= [NO2]² / [N2O4]
0.619 = (2x)² / (0.259-x)
0.619 = 4x² / (0.259 -x)
x = 0.1373
Step 7: Calculate concentrations
[N2O4] = (0.259 -x)M = 0.1217 M
[NO2]= 2x = 0.2746 M
Step 8: The moles
Moles = molarity * volume
Moles N2O4 = 0.1217 M * 2.10 = 0.0256 moles
Moles NO2 = 0.2746 M * 2.10 = 0.577 moles
Step 9: Calculate partial pressure
p*V = n*R*T
⇒ with p = the partial pressure
⇒ with V = the volume = 2.10 L
⇒ with n = the number of moles
⇒ with R = the gas constant = 0.08206 L*atm/mol*K
⇒ with T = the temperature = 45 °C = 318 K
p = (nRT)/V
p(N2O4) = (0.0256 *0.08206 * 318)/ 2.10
p(N2O4) = 0.318 atm
p(NO2) = (0.577 *0.08206 * 318)/ 2.10
p(NO2) = 7.17 atm
The beta-ketoester Claisen product is generated from the product of this final step by addition of dilute HCl. Write the final step of the Claisen condensation using curved arrows to show electron reorganization.
Answer:
This shown on the second uploaded image
Explanation:
What is occurring in this reaction is the further deprotonation of the base and this would now react with HCl to give the final product
Molten solder flows between the two base metals being soldered because ____. A. the atmospheric pressure pushes it in B. of capillary action C. there are no surface pores in the base metal D. the tubing surface melts and the pressure differential forces it in
Answer:
Molten solder flows between the two base metals being soldered because of capillary action.
Explanation:
Capillary molten solder takes place when a metal and a melt is brought into contact with the tube and an accessory after heating. Due to the phenomenon of capillary action, the molten metal rises and extends in any direction, due to the small space that remains between the wall of the tube and that of the fitting; With this, when cooling, a completely hermetic union is achieved.
Molten solder flows between two base metals due to capillary action, which allows the solder to spread evenly and adhere to the bases, metal ensuring a strong bond.
Explanation:Molten solder flows between the two base metals being soldered mainly because of a process known as capillary action. Capillary action is a natural occurrence where a liquid, in this case the molten solder, moves along a narrow space, such as between the two pieces of metal, against the force of gravity. The solder is drawn into the space and spread evenly between the two base metals because of the adhesive forces between the liquid and the surrounding materials are stronger than the cohesive forces within the liquid.
This phenomenon plays a fundamental role in the soldering process, as it allows the solder to spread evenly and adhere to the base metals, ensuring a strong and stable bond between them. This principle is used not only in soldering but also in various other fields such as plant biology, painting, and inkjet printing.
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A solution contains 35 g of NaCl per 100 g of water at 25 ∘C. Is the solution unsaturated, saturated, or supersaturated?
The solution described is saturated as it contains NaCl at a concentration equal to its solubility at 25°C, meaning water has dissolved the maximal amount of NaCl it can at that temperature.
Explanation:The solution you've described is a saturated solution, as it contains NaCl at a concentration equal to its solubility at a given temperature, in this case 25°C. This means that the water has dissolved as much sodium chloride as it can at this temperature, and any additional NaCl would not dissolve.
A supersaturated solution, on the other hand, is a solution that contains more solute than is possible under stable equilibrium conditions. This state is achieved by adding excess solute, or by evaporation of the solvent. A supersaturated solution is unstable, and will return to its saturation point upon disturbance, causing the excess solute to precipitate out.
Lastly, an unsaturated solution contains less solute than the maximum amount that can be dissolved in the solvent at a given temperature. In this state, more solute can be added and dissolved.
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The solution containing 35 g of NaCl per 100 g of water at 25 °C is unsaturated.
To determine the saturation status of the solution, we need to compare the actual amount of solute (NaCl) dissolved in the solvent (water) with the maximum amount that can be dissolved at a given temperature, which is known as the solubility of the solute in the solvent.
The solubility of NaCl in water at 25 °C is approximately 36 g per 100 g of water. Since the given solution has 35 g of NaCl per 100 g of water, this is less than the solubility limit. Therefore, the solution can still dissolve more NaCl and is considered unsaturated.
If the solution had exactly 36 g of NaCl per 100 g of water, it would be saturated, meaning it has reached its maximum capacity to dissolve NaCl at that temperature. If it had more than 36 g of NaCl per 100 g of water, it would be supersaturated, which is a state where the solution contains more solute than would normally be possible at equilibrium.
for the hypothetical reaction 2A B -> 2C D, the initial rate of disappearance of A is 1.6x10^-1 mol/(L s) . what is the initial rate of disappearance of B
Answer:
0.8 x10^-1 mol/(L s)
Explanation:
2A + B -> 2C + D
For the reaction above, the differential rate is usually expressed as;
Rate = - (1 / 2) Δ[A] / Δt = - Δ[B] / Δt
The negative sign denotes disappearance.
Upon comparing ; (1 / 2) Δ[A] / Δt = Δ[B] / Δt
If initial rate of disappearance of A is 1.6x10^-1 mol/(L s);
That means
Δ[B] / Δt = 1.6x10^-1 mol/(L s) / 2
Δ[B] / Δt = 0.8 x10^-1 mol/(L s)
The initial rate of disappearance of B = 1.6x10^-1 mol/(L s)