16.3 rate reactions

Question 1

what is the effect of concentration on zero order?

Answer 1

no effect

Question 2

what is the effect of concentration on first order?

Answer 2

rate of reaction is directly proportional

Question 3

what is the effect of concentration on second order?

Answer 3

rate of reaction is proportional to concentration squared

Question 4

what are the 4 assumptions in a initial-rate (iodine-clock) experiment?

Answer 4

1- constant temperature
2- [reactants] doesn’t change significantly
3- reaction not proceeded too far when end point is seen
4- rate of reaction remains constant

Question 5

how are different times taken recorded in reaction?

Answer 5

varying [I2] & [H2O2]

Question 6

why is a starch indicator used in the iodine-clock experiment?

Answer 6

when S2O3 2- is used up, I2 reacts with starch & produces blue-black colour

Question 7

what is the half-life?

Answer 7

time taken for 1/2 reactant to be used up

Question 8

what is the respective changes in half-life for 0, 1st and 2nd orders?

Answer 8

0- half-life decreases
1- half-life constant
2- half-life increases