CHEM126 – CHAPTER 14 – REGULAR HOMEWORK / EQUILIBRIUM I

CHAPTER 14 REGULAR HOMEWORK:

EQUILIBRIUM I

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Question 1

CHEM126 - CHAPTER 14 - REGULAR HOMEWORK / EQUILIBRIUM I 1

For the reaction: 2H2O(g) ↔ 2H2(g) + O2(g)

What are the correct values of x, y, and z for the equilibrium expression to be correct?

Select one or more:

 Correct

Explanation

 

Question 2

CHEM126 - CHAPTER 14 - REGULAR HOMEWORK / EQUILIBRIUM I 2

For the reaction: CO(g) + Cl2(g) ↔ COCl2(g)

What are the correct values of x, y, and z for the equilibrium expression to be correct?

Select one or more:
 Correct

Explanation

 

Question 3

CHEM126 - CHAPTER 14 - REGULAR HOMEWORK / EQUILIBRIUM I 3

For the reaction: CO2(g) ↔ CO(g) + 0.5O2(g)

What are the correct values of x, y, and z for the equilibrium expression to be correct?

Select one or more:
 Correct
Correct
f. y=”1
Correct

 

Question 4

CHEM126 - CHAPTER 14 - REGULAR HOMEWORK / EQUILIBRIUM I 4

For the reaction: Si(s) + O2(g) ↔ SiO2(s)

What are the correct values of x, y, and z for the equilibrium expression to be correct?

Select one or more:
 Correct

 

Question 5

CHEM126 - CHAPTER 14 - REGULAR HOMEWORK / EQUILIBRIUM I 5

At a certain temperature the equilbrium constant is 135 for

H2(g) + I2(g) ↔ 2HI(g)

Calculate the the equilbrium constant for

0.5H2(g) + 0.5I2(g) ↔ HI(g)

Correct

 

Question 6

The equilbrium constant for the water-gas shift reaction is 5.0 at 400 oC:CO(g) + H2O(g) ↔ CO2(g) + H2(g)

Determine Qc if the following amounts (in moles) of each component is placed in a 1.0 L container.

CO 0.53
H2O 0.27
CO2 0.89
H2 0.65

Correct

Explanation

 Keq= 5

Q= [CO2][H2]/[CO][H20]

Q=[0.89][0.65]/[0.53][0.27]= 4.04

Question 7

What is the direction of the reaction for the above conditions?
Select one:
 Correct

Explanation

 Q<Keq

goes to right

Question 8

Determine Qc if the following amounts (in moles) of each component is placed in a 1.0 L container.

CO 0.34
H2O 0.11
CO2 0.88
H2 0.80

Correct

Explanation

 Q = [.88][.8]/[.11][.34]

=18.82

Question 9

What is the direction of the reaction for the above conditions?
Select one:
 Correct

Explanation

 Q>Keq

goes to the left

Question 10

The equilbrium constant for the following reaction is 0.16 M0.5 at 3000 K:

CO2(g)  CO(g) + 0.5O2(g)

Determine Qc if the following amounts (in moles) of each component is placed in a 3.00 L container.

CO2 0.900
CO 0.840
O2 0.200

Give answer to 3 decimal places.

Correct

Explanation

 Remember to use concentration (mol/L)!!

Q= [O2]^.5[CO]/[CO2]

Q= (0.2/3)^.5(0.840/3)/(.900/3)

Q=.242

Question 11

What is the direction of the reaction for the above conditions?
Select one:
 Correct

Explanation

 Q> K

goes to the left

Question 12

Determine Qc if the following amounts (in moles) of each component is placed in a 10.00 L container.

CO2 0.560
CO 0.260
O2 0.560

Correct

Explanation

Q= [O2]^.5[CO]/[CO2]
Q= [.560/10]^.5[.260/10]/[.560/10]

Q=.11

Question 13

What is the direction of the reaction for the above conditions?
Select one:
 Correct

Explanation

 Q<Keq

goes to the right

Question 14

Phosgene is formed from carbon monoxide and chlorine. At 607 oC, Kc is approximately 13.5 M-1 or L/mol. Calculate Kp (in atm-1) at this temperature.

CO(g) + Cl2(g) ↔ COCl2(g)

Correct

Explanation

 Kp = Kc (RT)^deltan

Kp= 13.5 (0.0821*(607-273.15)^1

Kp= .187

Question 15

Some ammonia is sealed in a container and allowed to equilibrate at a particular temperature. The reaction is endothermic.

2NH3(g) ↔ N2(g) + 3H2(g)

In which direction will the reaction occur if some ammonia is removed from the system?

Select one:
 Correct

CHEM126 - CHAPTER 14 - REGULAR HOMEWORK / EQUILIBRIUM I 6

Question 16

In which direction will the reaction occur if some hydrogen is removed from the system?
Select one:
 Correct

Question 17

In which direction will the reaction occur if the volume of the container is decreased?
Select one:
 Correct

 

Question 18

In which direction will the reaction occur if the temperature is increased?
Select one: Correct

 

Question 19

In which direction will the reaction occur if argon is added to the system at constant volume. Thus, increasing the total pressure in the container?
Select one:
 Correct

 

Question 20

Chemists studied the formation of phosgene by sealing 0.76 atm of carbon monoxide and 1.14 atm of chlorine in a reactor at a certain temperature. The pressure dropped smoothly to 1.32 atm as the system reached equilbrium. Calculate Kp (in atm-1) for

CO(g) + Cl2(g) ↔ COCl2(g)

Correct

Explanation

Hint, find the final pressure of each gas.

Use ICE Tables to solve:

CO Cl2 COCl2

I 0.76 1.14 0
C -x -x +x
E 0.76-x 1.14 -x x

1.32 = (0.76-x)+ (1.14-x)+x
Solve: -x=-0.58
x=0.58

CO Cl2 COCl2
I 0.76 1.14 0
C -0.58 -0.58 0.58
E 0.18 0.56 0.58

([0.58]/[0.18][0.56]) = 5.75

Question 21

Consider 1.80 mol of carbon monoxide and 3.80 mol of chlorine sealed in a 4.00 L container at 476 oC. The equilibrium constant, Kc, is 2.50 for

CO(g) + Cl2(g) ↔ COCl2(g)

Calculate the equilibrium molar concentration of CO.

Correct

Explanation

Hint, you need to find the equilibrium concentrations of all the gases. Note, that only one of the solutions to the quadratic equation makes sense (the other gives at least one negative concentration).

CO(g) + Cl2(g) ↔ COCl2(g)

I 1.8/4     3.8/4        0

C -x         -x           +x

E 1.8/4 -x   3.8/4 -x   x

Kc = 2.5 = x/ (1.8/4 -x)(3.8/4-x)

x=.2815

1.8/4 – .2815 = .1685