C6

Question 1

Activation energy

Answer 1

Minimum amount of energy that particles need to react

Question 2

How do catalysts work in increasing rate of reaction

Answer 2

Decrease activation energy needed for reaction to occur by providing an ‘alternative reaction pathway’ with a lower activation energy
Different catalysts needed for different reactions

Question 3

Rate of reaction =

Answer 3

Amount of reactant used or amount of product formed / time

Question 4

Rate of reaction practical

Answer 4

Observe a mark (X) through solution
Time from when reaction starts to reaction ends - shown by X being invisible

Question 5

Rate of reaction practical drawbacks

Answer 5

• subjective to when X disappears
• cannot plot a graph

Question 6

Change in mass ROR practical

Answer 6

• use mass balance to measure as gas is released, reading drops
• the quicker reading on balance drops, the quicker the faster the reaction
  Taking measurements at regular intervals allows plotting of graph to find rate

Question 7

Volume given off ROR practical

Answer 7

• Gas syringe used to measure volume of gas given off
• the more gas given off during given time interval, the faster the reaction
  Taking measurements at regular intervals allows plotting of graph to find rate

Question 8

if concentration is increased

Answer 8

system tries to decrease it by making more products

Question 9

if concentration is decreased

Answer 9

system tries to increase it by reducing amount of reactants

Question 10

if pressure is increased

Answer 10

equilibrium moves in direction where there are fewer molecules of gas

Question 11

if pressure is decreased

Answer 11

equilibrium moves in direction where there are more molecules of gas

Question 12

if temperature is increased

Answer 12

equilibrium will move in endothermic direction to try and decrease it

Question 13

if temperature is decreased

Answer 13

equilibrium will move in exothermic direction to try and decrease it