CHE 105/110 Introduction to Chemistry - Exercises and Answers

1.

Define Le Chatelier’s principle.

1.

When an equilibrium is stressed, the equilibrium shifts to minimize that stress.

3.

Given this equilibrium, predict the direction of shift for each stress.

$${\text{H}}_{\text{2}}{\text{(g) + I}}_{\text{2}}\text{(s) + 53 kJ}\rightleftarrows \text{2HI(g)}$$

1. decreased temperature
2. increased pressure
3. removal of HI

3.

1. toward reactants
2. toward reactants
3. toward products

5.

Given this equilibrium, predict the direction of shift for each stress.

$${\text{2SO}}_{\text{2}}{\text{(g) + O}}_{\text{2}}\text{(g)}\rightleftarrows {\text{2SO}}_{\text{3}}\text{(g) + 196 kJ}$$

1. removal of SO₃
2. addition of O₂
3. decreased temperature

5.

1. toward products
2. toward products
3. toward products

7.

The synthesis of NH₃ uses this chemical reaction.

$${\text{N}}_{\text{2}}{\text{(g) + 3H}}_{\text{2}}\text{(g)}\rightleftarrows 2{\text{NH}}_{\text{3}}\text{(g) + 92 kJ}$$

7.

increased pressure, decreased temperature, removal of NH₃