[ Home ] [ Pre AP/IB Chem ] [ AP/IB Chem ] [ IB Chem ] [ Chem Online ]

 
Name: 
 

EQUILIBRIUM


Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

1. 
At equilibrium,
a.
all reactions have ceased.
b.
only the forward reaction continues.
c.
only the reverse reaction continues.
d.
both the forward and reverse reactions continue.
 

2. 
At equilibrium,
a.
the forward reaction rate is lower than the reverse reaction rate.
b.
the forward reaction rate is higher than the reverse reaction rate.
c.
the forward reaction rate is equal to the reverse reaction rate.
d.
no reactions take place.
 

3. 
At equilibrium, the total amount of the product(s)
a.
is always equal to the total amount of the reactants.
b.
is always greater than the total amount of the reactants.
c.
is always less than the total amount of the reactants.
d.
may be equal to, greater than, or less than the total amount of the reactants.
 

4. 
How does the value of K show that a reaction reaches equilibrium very quickly?
a.
K is large.
b.
K is small.
c.
K is zero.
d.
The value of K does not show how quickly a reaction comes to equilibrium.
 

5. 
A very low value of K indicates that
a.
equilibrium is reached slowly.
c.
reactants are favored.
b.
products are favored.
d.
equilibrium has been reached.
 

6. 
What is the chemical equilibrium expression for the equation

2A2B + 3CD equilibrium_files/i0070000.jpg A4D + C3B2?
a.
equilibrium_files/i0070001.jpg
c.
equilibrium_files/i0070002.jpg
b.
equilibrium_files/i0070003.jpg
d.
equilibrium_files/i0070004.jpg
 

7. 
An equilibrium mixture of SO2, O2, and SO3 gases at 1500 K is determined to consist of 0.344 mol/L SO2, 0.172 mol/L O2, and 0.56 mol/L SO3. What is the equilibrium constant for the system at this temperature? The balanced equation for this reaction is

2SO2(g) + O2(g) equilibrium_files/i0080000.jpg 2SO3(g).
a.
0.41
c.
6.7
b.
2.8
d.
0.15
 

8. 
If the pressure on the equilibrium system 2CO(g) + O2(g) equilibrium_files/i0090000.jpg 2CO2(g) is increased,
a.
the quantity of CO(g) increases.
b.
the quantity of CO2(g) decreases.
c.
the quantity of CO2(g) increases.
d.
the quantities in the system do not change.
 

9. 
If the pressure on the equilibrium system N2(g) + O2(g) equilibrium_files/i0100000.jpg 2NO(g) decreases,
a.
the quantity of N2(g) decreases.
b.
the quantity of NO(g) increases.
c.
the quantity of NO(g) decreases.
d.
the quantities in the system do not change.
 

10. 
If the temperature of the equilibrium system CH3OH(g) + 101 kJ equilibrium_files/i0110000.jpg CO(g) + 2H2(g) increases,
a.
[CH3OH] increases and [CO] decreases.
b.
[CH3OH] decreases and [CO] increases.
c.
[CH3OH] increases and [CO] increases.
d.
the concentrations in the system do not change.
 

11. 
In a 1.0-liter container there are, at equilibrium, 0.20 mole of I2, 0.30 mole of H2, and 0.20 mole of HI. What is the value of Kc for the reaction?
H2(g) + I2 (g) ß à2HI(g)
a.
0.33
c.
2.7
b.
0.67
d.
1.3
 

12. 
Nitrosyl chloride, NOCl, dissociates on heating as shown below. When a 1.50-gram sample of pure NOCl is heated at 350oC in a volume of 1.00 liter, the percent dissociation is found to be 57.2%. Calculate the equilibrium concentration of NOCl.
 NOCl(g) ßà ½ NO(g) + Cl-(g)
a.
8.76 X 10-1 M
c.
9.80 X 10-3 M
b.
9.26 M
d.
1.31 X 10-2 M
 

13. 
The equilibrium constant for the following gas phase reaction is 4.0 at a certain temperature. A reaction is carried out at this temperature starting with 2.0 mol/L of CO and 2.0 mol/L of H2O  . What will be the equilibrium concentration of H2?
              CO + H2O  ßà  CO2 + H2
a.
2.0 M
c.
1.3 M
b.
0.75 M
d.
0.67 M
 



 
Check Your Work     Reset Help