6.2- CHANGING THE CONDITIONS OF AN EQUILIBRIUM REACTION

Question 1

What would reversible reactions in a closed system produce?

Answer 1

equilibrium mixtures containing both products + reactants

Question 2

Examples of industrial processes that have reversible reactions as a key step?

Answer 2

production of ammonia or sulfuric acid

Question 3

If the proportion of products in equilibrium mixture increased, where does equilibrium move?

Answer 3

equilibrium moves to right, or in forward direction

Question 4

If the proportion of reactants in equilibrium mixture increased, where does equilibrium move?

Answer 4

equilibrium moves to right, or in forward direction

Question 5

How can you move the equilibrium position to the left or right?

Answer 5

by varying conditions i.e. temp, concentration of species involved, or pressure (in cases of reactions involving gases)

Question 6

What does Le Chatelier’s principle state?

Answer 6

if system at equilibrium disturbed, equilibrium moves in direction that tends to reduce disturbance

Question 7

If any factor is changed which affects the equilibrium mixture, what will the position of equilibrium change to do?

Answer 7

position of equilibrium will shift as to oppose the change

Question 8

What does Le Chatelier’s principle not tell us and so what can we not predict?

Answer 8

does not tell us how far the equilibrium moves so cannot predict the quantities involved

Question 9

What does Le Chatelier’s principle say if you increase the concentration of one of the reactants?

Answer 9

equilibrium will shift in direction that tends to reduce concentration of this reactant

Question 10

What do you end up with if you increase the concentration of one of the reactants?

Answer 10

end up with greater proportion of products in reaction mixture

Question 11

What would happen if you remove C as it forms? A + B = C + D

Answer 11

equilibrium would move to right to produce more C (+ D) using up A + B

Question 12

When do pressure changes affect a reaction?

Answer 12

only affect reactions involving gases

Question 13

What will changing the overall pressure change?

Answer 13

will only change position of equilibrium of gaseous reaction if there are a different number of molecules on either side of reaction

Question 14

What does increasing the pressure of a gas mean?

Answer 14

there are more molecules of it in given volume

Question 15

What is equivalent to increasing the pressure but for solution?

Answer 15

increasing conc. of solution

Question 16

What affect does pressure have if there is the same number of moles of gases on both sides of the equation?

Answer 16

pressure has no effect on equilibrium position

Question 17

If one direction of a reversible reaction is exothermic, what is the other side like?

Answer 17

endothermic

Question 18

What is the size of enthalpy like on both sides of a reversible reaction?

Answer 18

size of enthalpy same in both directions but signs change

Question 19

What happens if you increase the temperature of equilibrium mixture that’s exothermic in forward reaction?

Answer 19

equilibrium mixture will contains greater proportion of reactants

Question 20

Do catalysts have an effect on the position of equilibrium?

Answer 20

no

Question 21

What do catalysts work by doing?

Answer 21

work by producing alternative route for reaction, which has lower activation energy of reaction

Question 22

Which direction of a reversible reaction does a catalyst affect?

Answer 22

affects forward + back reactions equally

Question 23

What do catalysts allow equilibrium to do?

Answer 23

allow equilibrium to be reached more quickly + so important in industry