Rates of reaction

Question 1

how to measure rate of reaction

Answer 1

amount of products formed / time

OR

amount of reactant used up / time

Question 2

three ways of measuring rate?

Answer 2

• measuring volume of gas produced (gas syringe)
• measuring change in mass ( balance )
• measuring time taken for a colour change (stop watch)

Question 3

when measuirng the volume of gas produced , when is the IV, DV and CV

Answer 3

IV - concentration of acid or SA of marble chips

DV - volume of gas produced

CV - temp, volumes, pH

Question 4

when measuring time taken for colour change, what are the IV, DV and CV

Answer 4

IV - temperature of solution

DV - time taken for cross to disappear

CV - concentration, volume , mass

Question 5

what is activation energy?

Answer 5

the minimum amount of energy required for reactants to start forming products

Question 6

give the four factors that affect rate of reaction

Answer 6

• temp
• concentration
• pressure
• surface area

Question 7

define a catalyst

Answer 7

a substance that speeds up the rate of reactions without being chemically changed or used up. It doesn’t alter products and the catalyst doesnt change in mass

Question 8

why does lowering activation energy increase rate of reaction?

Answer 8

less energy is required for particles to collide succesfully

Question 9

what is an enzyme and what is it used for?

Answer 9

• biological catalyst

- used in fermination to produce alcoholic drinks