rate of reaction

Question 1

how should the rate of these reactions be measured

Answer 1

A) massB) light transmittedC) volume-gas evolved from reaction mixtture- C/A- Mass of reaction mixture changes A- precipitate produced B- colour or solution changes B

Question 2

collision theory

Answer 2

• more collisions increases the rate of reaction
• 4 methods can be used:
  -temperature- when the temp is increased, the particles gain energy and move quicker. more successful collisions per second
• concentration:- more particles of reactant between water molecules
• collisions between important particles are more likely
  pressure:
• particles more squashed resulting in more collisions
  surface area:
• if a reactant is a solid, breaking it up into smaller pieces will increase the surface area. more area for successful collisions to occur in
  catalyst:
  -provides a surface area upon which the reacting particles can stick to
• provides more opportunities to bump into eachother.

Question 3

pros and cons of using a catalyst

Answer 3

pros: - increase productivity- lower the temp- reduce costs- can be reused- faster reaction
cons: - often expensive- only wok for one reaction- impurities stop them working so need to be replaced

Question 4

effect of concentration on rates experiment

Answer 4

CaCO3 +2 HCl -> CO2 + CaCl2 + H2O

1) make up 20 ml of hydrochloric acid ; mix 2.0 mol/dm(*3) hydrochloric acid with water. place the solution in the boiling tube
2) weigh out 2g of calcium carbonate chips in a weighing bbottle
3) add calcium carbonate chips to the acid and immediately insert the bung
4) measure the volume of CO2 gas formed in 30 seconds

Question 5

rate of reaction

Answer 5

• rate = change in amount of reactant/ time- measure: