Tricky topics

Question 1

What happens if the reactant concentration increases, to a system at equilibrium ?

Answer 1

• when the reactant concentration increases, more products will be formed.
• this is because of Le Chatelier’s principle therefore, it will counteract the change-by equilibrium shifting to reduce the reactant concentration, as the reaction forming products is favoured
• this decreases the concentration of the reactant.

Question 2

What happens if the product concentration increases, to a system at equilibrium ?

Answer 2

• if the product concentration increases, equilibrium will shift to reduce the product concentration.
• this is because of le chatelier’s principle therefore, the reaction forming reactants will be favoured

Question 3

How can a system, decrease the concentration of a reactant ?

Hint: favouring

Hint #2: rate at which…

Answer 3

• a system, can decrease the concentration of a reactant by:
• increasing the rate at which the reactant is used up, and favouring the forward reaction.
• this increases the rate of formation of the product- until equilibrium is established again

Question 4

Regarding pressure, what happens if the forwards reaction produces more molecules of gas ?

Hint: yield

Answer 4

• if the forwards reaction produces more molecules of gas:
• an increase in pressure will decrease the yield of products formed
• ; a decrease in pressure, will increase the yield of product formed

Question 5

Regarding pressure, what happens if the forwards reaction produces fewer molecules of gas ?

Answer 5

• if the forwards reaction produces fewer molecules of gas:
• an increase in pressure, will increase the yield of product formed
• ; a decrease in pressure, will decrease the yield of product formed

Question 6

Regarding temperature, what happens if the forward reaction is exothermic ?

Hint: increase and decrease

Answer 6

• if the forward reaction is exothermic:
• an increase in temperature, decreases the yield of product formed
• ; a decrease in pressure, increases the yield of products formed

Question 7

Regarding temperature, what happens if the forward reaction is endothermic ?

Hint: increase and decrease

Answer 7

• if the forward reaction is endothermic:
• an increase in temperature increases the yield of product formed
• ; a decrease in pressure, decreases the yield of product formed

Question 8

What happens if the temperature increases, to a system at equilibrium ?

Answer 8

• if the temperature increases, the position of equilibrium will shift to reduce the temperature.
• this is because of le chatelier’s principle therefore, the endothermic reaction will be favoured

Question 9

What happens if the temperature decreases, to a system at equilibrium ?

Answer 9

• if the temperature decreases, equilibrium will shift to increase the temperature.
• this is because of le chatelier’s principle so, the exothermic reaction will be favoured

Question 10

What happens if the pressure is increased, to a system at equilibrium ?

Answer 10

• if the pressure is increased, the position of equilibrium will shift to reduce the pressure.
• therefore the side of the reaction with fewer gas molecules, will be favoured

Question 11

What happens if the pressure is decreased, to a system at equilibrium ?

Answer 11

• if the pressure is decreased, the position of equilibrium will shift to reduce the pressure.
• this is because of le chatelier’s principle, therefore the side of the reaction with more gas molecules will be favoured