The rate equation for the reaction between iodine and propanone is:

rate = k[CH₃COCH₃] [H⁺] [I₂]⁰

a. State the order of reaction with respect to iodine.

b. State the overall order of reaction.

c. i. What is meant by the term half-life?

ii. In an experiment a large excess of iodine is reacted with a small concentration of propanone in the presence of H⁺(aq). The concentration of propanone is measured at regular time intervals. What happens to the value of the half-life of the propanone concentration as the concentration of propanone decreases?

d. Copy the sketch graph. Plot additional points at 10-second intervals up to 50 s. Join all the points with a smooth curve.

e. Explain the term rate-determining step.

f. Suggest a possible mechanism for the rate-determining step for the reaction between iodine and propanone.

Transcribed Image Text:

8 * 6 0+ 10 20 30 40 50 60 Time/s [propanone] /mol dm3 2.