Le Chatelier's Principle

What type of reactions can able to change products back to their original form?

• Irreversible reactions

• Combustion reactions

• Reversible reactions

Which of the following changes is irreversible change?

• Frying an egg

• Heating hydrated CuSO4

• Thermal decomposing NH4Cl

• Melting of ice cube

A substance that increases speed of chemical reaction without being changed is called:

• Acid

• Catalyst

• Base

• Pressure

Increase in temperature of the reactants can do one of the following

• Cause particles to lose speed

• Allow less effective collision between the particles

• Slow collision frequency

• Increase collision between the particles thus increasing the rate.

2SO₂(g) + O₂(g) ⇌ 2SO₃(g) + Heat. Adding SO₂(g) will:

• increase rate of reaction

• shift equilibrium left

• shift equilibrium right

• have no change

2SO₂(g) + O₂(g) ⇌ 2SO₃(g) + Heat. Increasing the temperature will:

• increase pressure

• shift equilibrium right

• shift equilibrium left

• have no change

2SO₂(g) + O₂(g) ⇌ 2SO₃(g) + Heat. Removing O₂(g) will:

• increase pressure

• shift equilibrium right

• shift equilibrium left

• have no change

2SO₂(g) + O₂(g) ⇌ 2SO₃(g) + Heat. Using a catalyst:

• shift equilibrium left

• shift equilibrium right

• have no effect because it speeds the reaction in both directions

• Position of equilibrium will shift to left (and become more blue)

• Position of equilibrium will shift to right (and become more pink)

• Position of equilibrium will shift to left to reduce the added H2O

Heat + 1 N2O4 → 2 NO2. What will happen when the temperature is increased?

• Position of equilibrium will shift to right and become lighter in color

• Position of equilibrium will shift to right and become more brown

• Position of equilibrium will shift to left and become lighter in color

• No change in position of equilibrium