Changing the conditions of an equilibrium reaction 2

Question 1

Do pressure changes affect all reactions?

Answer 1

No, pressure changes only affect reactions involving gases

Question 2

When will changing the pressure affect the position of equilibrium in a gaseous reaction?

Answer 2

Only if there is a different number of gas molecules on either side of the equation

Question 3

What happens to the equilibrium when the pressure is increased?

Answer 3

The equilibrium moves to the side with fewer gas molecules, reducing the pressure

Question 4

What happens to the equilibrium when the pressure is decreased?

Answer 4

The equilibrium will move to the side with more gas molecules, increasing the pressure

Question 5

What happens to the equilibrium in the reaction N2O4(g) ↔ 2NO2(g) when the pressure is decreased?

Answer 5

The equilibrium will shift to the right producing more NO2, which increases the pressure

Question 5

How is increasing the pressure a gas similar to increasing the concentration of a solution?

Answer 5

Increasing the pressure means there are more gas molecules in a given volume, just like increasing concentrations means more solute particles in a given volume

Question 5

What happens to the equilibrium in the reaction N2O4(g) ↔ 2NO2(g) when the pressure is increased?

Answer 5

The equilibrium will shift to the left because there are fewer gas molecules (N2O4 - 1 mole) on that side, reducing the pressure

Question 6

What happens to the equilibrium position if there is the same number of gases on both sides of the equation?

Answer 6

The equilibrium position does not change when pressure is altered

Question 7

Why does pressure have no effect on equilibrium if there are equal moles of gases on both sides?

Answer 7

Changing the pressure does not favour either side, as both sides exert the same number of gas molecules

Question 8

What is the relationship between exothermic and endothermic reactions in a reversible reaction?

Answer 8

Reversible reactions that re exothermic in one direction are endothermic in the other direction

Question 9

How does the enthalpy change compare for the forward and reverse reactions?

Answer 9

The size of enthalpy change is the same for both directions, but the sign changes

Question 10

What happens if you increase the temperature of an equilibrium mixture where the forward reaction is exothermic?

Answer 10

The equilibrium shifts to the left (endothermic direction) to absorb the added heat

Question 10

Why does the equilibrium shift to the endothermic direction when the temperature is increased?

Answer 10

According to Le Châtelier’s principle, this is done to oppose the temperature increase by absorbing the heat

Question 11

How does increasing the temperature affect the proportions of products and reactants in an exothermic forward reaction?

Answer 11

The proportion of reactants increases, and the proportion of products decreases

Question 12

What happens to the equilibrium if you decrease the temperature in a reaction exothermic in the forward direction?

Answer 12

The equilibrium shifts to the right (exothermic direction), producing more products

Question 13

What does the negative ΔH value indicate about a reaction?
What does the positive ΔH value indicate about a reaction?

Answer 13

It means the forward reaction is exothermic, releasing heat. It means the forward reaction is endothermic, absorbing heat

Question 13

What happens to the equilibrium when the temperature is decreased in an exothermic reaction?

Answer 13

The equilibrium shifts to the right (exothermic direction), releasing heat

Question 14

Why does the equilibrium move in the endothermic direction when the temperature increases?

Answer 14

To release heat and counteract the temperature drop

Question 15

Do catalysts affect the position of equilibrium?

Answer 15

No, catalysts do not affect the position of equilibrium or the composition of the equilibrium mixture

Question 16

How do catalysts speed up a reaction?

Answer 16

Catalysts provide an alternative reaction pathway with a lower activation energy for the reaction

Question 16

What is the primary benefit of using catalysts in equilibrium reactions?

Answer 16

Catalysts reduce the time needed to reach equilibrium, making processes more efficient

Question 17

How do catalysts affect the forward and backward reactions in a reversible reaction?

Answer 17

Catalysts affect the forward and backward reactions equally, increasing the rate of both