Equilibrium Quiz #2- LeChateliers Principle

Equilibrium Quiz #2 LeChatelier’s Principle Answers

1. Consider the following reaction: 2SO_2(g)+ O_2(g)⇄ 2SO_3(g)∆H = -197 kJ/mol

Which of the following will not shift the equilibrium to the right?

A. Adding more O₂

B. Adding a catalyst

C. Increasing the pressure

D. Lowing the temperature

2. Consider the following equilibrium system: CaCO_{3(s) ⇄} CaO_(s) + CO_2(g)

Which one of the following changes would cause the above system to shift left?

A. Add more CaO

B. Remove CaCO₃

C. Decrease volume

D. Increase surface area of CaO

3. Consider the following equilibrium: SO₂Cl₂₍_g)+ energy ⇄ SO_2(g)+ Cl_2(g)

When the temperature is decreased, the equilibrium shifts

A. Left and [ SO₂Cl₂ ] increases

B. Left and [ SO₂Cl₂ ] decreases

C. Right and [ SO₂Cl₂ ] increases

D. Right and [ SO₂Cl₂ ] increases

4. Consider the following equilibrium: 2SO₃₍_g) ⇄ 2SO_2(g)+ O_2(g)

The volume of the system is decreased at a constant temperature. A new state of equilibrium is established

by a shift of the original equilibrium to the

A. Left and [SO₃] increases

B. Right and [SO₃] decreases

C. Left and [SO₃] remains unchanged

D. Right and [SO₃] remains unchanged

5. Consider the following equilibrium system: CO_2(g)+ H_2(g)⇄ CO_(g) + H₂O_(g)

Which of the following, when added to the system above, would result in a net decrease in [H₂O]?

A. CO₂

B. H₂

C. CO

D. H₂

6. Consider the following equilibrium: C_{(s) +} 2H_2(g)⇄ CH_4(g)+ 74 kJ

When a small amount of solid C is added to the system

A. [H₂] decreases

B. [CH₄] increases

C. The temperature increases

D. All concentrations remain constant

7. Consider the following equilibrium: 2NO₍_g) + Cl_2(g)⇄ 2NOCl_(g)

At constant temperature and volume, Cl₂ is added to the above equilibrium system.

As equilibrium re-establishes, the

A. [NOCl] will decrease

B. The temperature increases

C. [NO] will increase

D. [NOCl] will increase

8. Consider the following equilibrium: Cl₂O₇₍_g)+8H_2(g)⇄ 2HCl_(g)+ 7H₂O_(g)

Which of the following would increase the number of moles of HCl?

A. Increase [H₂O]

B. Increase [Cl₂O₇]

C. Increase total pressure

D. Increase volume of the system

9. Consider the following equilibrium: 2HI₍_g) ⇄ H_{2(g) +}I_2(g)∆H = -68kJ

Which of the following would cause the equilibrium to shift right?

A. Increasing the volume

B. Decreasing the volume

C. Increasing the temperature

D. Decreasing the temperature

10. A 1.00 L flask contains a gaseous equilibrium system. The addition of reactants to this flask results in a

A. Shift to the left and decrease in the concentration of products

B. Shift to the left and increase in the concentration of products

C. Shift to the right and decrease in the concentration of products

D. Shift to the right and increase in the concentration of products

11. When the temperature of an equilibrium system is increased, the equilibrium always shifts to favor the

A. Exothermic reaction

B. Endothermic reaction

C. Formation of products

D. Formation of reactants

12. An equilibrium system shifts left when the

A. Rate of the forward reaction is equal to the rate of the reverse reaction

B. Rate of the forward reaction is less than the rate of the reverse reaction

C. Rate of the forward reaction is greater than the rate of the reverse reaction

A. Rate of the forward reaction and the rate of the reverse reaction are constant

13. Consider the following equilibrium: 2SO₂₍_g)+ O_2(g)⇄ 2SO_3(g)∆H = -198 kJ

There will be no shift in the equilibrium when

A. More O₂ is added

B. Catalyst is added

C. The volume is increased

D. The temperature is increased

14. Consider the following equilibrium: 2NOCl₍_g) ⇄ 2NO_(g) + Cl_2(g)

In a 1.0 L container at equilibrium there are 1.0 mol NOCl, 0.70 mol NO and 0.40 mol Cl₂.

At constant temperature and volume, 0.10 mol NOCl is added. The concentrations in the

“new” equilibrium in comparison to the concentrations in the “old” equilibrium are

A.

B.

C.

D.

[NOCl]	[NO]	[Cl2]
new = old	new = old	new = old
new > old	new > old	new > old
new < old	new < old	new > old
new < old	new > old	new > old

15. Consider the following equilibrium: N₂O₄₍_g)+ 58 kJ ⇄ 2NO_2(g)

The equilibrium shifts right when

A. NO₂ is added

B. N₂O₄ is removed

C. The temperature is decreased

D. The volume of the system is increased

16. Consider the following equilibrium: 2SO₂₍_g)+ O_2(g)⇄ 2SO _3(g)

Which of the following will shift the equilibrium to the right?

I. Adding more O₂

II. Adding more SO₃

III. Adding a catalyst

A. I only

B. III only

C. I and II only

D. II and III only

17. Consider the following equilibrium:

energy + 2NaClO_3(s) ⇌ 2NaCl_(s) + 3O_2(g)

Which of the following will cause a shift to the left?

A. adding more O₂

B. adding more NaCl

C. removing some NaClO₃

D. increasing the temperature

18. Consider the following equilibrium:

CO₍_g) + 2H_2(g)⇌ CH₃OH_(g)+ energy

Which of the factors below would decrease the concentration of CH₃OH at equilibrium?

A. an addition of CO

B. an increase in H₂

C. a decrease in the temperature

D. an increase in the temperature

19. Consider the following equilibrium:

energy + 2NaClO_3(s) ⇌ 2NaCl_(s) + 3O_2(g)

Which of the following will cause a shift to the right?

A. adding more O₂

B. adding more NaCl

C. removing some NaCl_(s)

D. increasing the temperature

20. Consider the following equilibrium: 2SO₂₍_g)+ O_2(g)⇄ 2SO _3(g)

Which of the following will shift the equilibrium to the left?

I. Removing O₂

II. Adding more SO₃

III. Adding a catalyst

A. I only

B. III only

C. I and II only

D. II and III only

21. Consider the following equilibrium: N₂O₄₍_g)+ energy ⇌ 2NO_2(g)

How are N₂O₄ and NO₂affected by the addition of He into the container at constant volume.

N₂O₄NO₂

A. no change no change

B. no change increases

C. increases decreases

D. decreases increases

22. Which of the following stresses will cause a shift to the reactants?

H₂₍_g)+ Br_2(g)⇌ 2HBr_(g) + energy

A. increase [Br₂]

B. increase [H₂]

C. decrease temperature

D. increase temperature

23. Which of the following stresses will cause a shift to the products?

H₂₍_g)+ Br_2(g)⇌ 2HBr_(g) + energy

A. decrease [Br₂]

B. decrease [H₂]

C. decrease temperature

D. increase temperature

24. Which of the following two stresses will each cause the system to shift to the left?

2SO₂₍_g)+ O_2(g)⇄ 2SO _3(g) + energy

A. decrease temperature and decrease [O₂]

B. increase temperature and increase [SO₃]

C. increase temperature and decrease [SO₃]

D. decrease temperature and increase [SO₂]

25. SrCO_3(s)+ 215 kJ ⇌ SrO_(s) + CO_2(g)

Which of the following conditions would produce the greatest yield of SrO_(s)?

Temperature Pressure

A. low low

B. low high

C. high low

D. high high

26. The Haber Process is used to produce ammonia commercially according to the following equilibrium:

N₂₍_g) + 3H_2(g)⇌ 2NH_3(g) + energy

Which of the following conditions will produce the highest yield of ammonia?

A. increase temperature and increase pressure

B. increase temperature and decrease pressure

C. decrease temperature and increase pressure

D. decrease temperature and decrease pressure

27. Consider the following reaction: 2SO_2(g)+ O_2(g)⇄ 2SO_3(g)∆H = -197 kJ/mol

If the volume is increased what happens to position of the equilibrium?

A. shifts to the right

B. shifts to the left

C. no shift