Le Chatelier's Principle

Question 1

What does Le Chatelier’s principle state?

Answer 1

If there’s a change in temperature, pressure or concentration in a reversible reaction, the equilibrium position will move to help counteract that change.

Question 2

All reactions are what and what in each direction?

Answer 2

Exothermic in one direction, and endothermic in the other.

Question 3

What will happen if you decrease the temperature?

Answer 3

The equilibrium will move in the exothermic direction to produce more heat.

Question 4

What will happen if you increase the temperature?

Answer 4

The equilibrium will move in the endothermic direction to absorb the extra heat.

Question 5

Changing pressure only affects what state?

Answer 5

Gases.

Question 6

What will happen if you increase the pressure?

Answer 6

The equilibrium will move towards the side that has fewer moles of gas to reduce pressure.

Question 7

What will happen if you decrease the pressure?

Answer 7

The equilibrium will move towards the side that has more moles of gas to increase pressure.

Question 8

What will happen if you increase the concentration of the reactants?

Answer 8

The equilibrium will move to the right to use up the reactants (making more products).

Question 9

What will happen if you decrease the concentration of the reactants?

Answer 9

The equilibrium will move to the left to use the products (making more reactants).

Question 10

What will happen if you increase the concentration of the products?

Answer 10

The equilibrium will move to the left to use up the products (making more reactants).

Question 11

What will happen if you decrease the concentration of the products?

Answer 11

The equilibrium will move to the right to use up the reactants (making more products).

Question 12

How does temperature affect the Haber process?

Answer 12

N2 + 3H2 ⇌ 2NH3

This reaction is exothermic in the forward direction. If you decrease the temperature, the equilibrium will shift to the right (so you’ll make more products).

Question 13

How does pressure affect the Haber process?

Answer 13

N2 + 3H2 ⇌ 2NH3

This reaction has 4 moles of gas on the left, and 2 on the right. If you increase the pressure, the equilibrium will shift to the right (so you’ll make more product).

Question 14

How does concentration affect the Haber process?

Answer 14

N2 + 3H2 ⇌ 2NH3

If you increase the concentration of N2 or H2, the equilibrium will shift to the right to use up the extra reactants (so you’ll make more products).