Question

I'm doing the Iodide- Catalyzed Decomposition Kinetics of H2O2 lab .
One of the post lab questions asks, " Based on these plots determine the rate law of this reaction and the corresponding average k' and k" values."

and

"Determine the average value of the rate constant, k, and the standard deviation in your calculated values of k from individual runs."

What are these questions saying and how do I utilize the formula to calculate this answer. I really need help.
I have two graphs I've determined that they're both first order reactions . Now what.

Answer 1

For the Iodine clock reaction,

lets say rate law for the reaction be written as,

rate = k'[H2O2]^x.[H+]^y.[I-]^z

From this,

k' = rate constant

x, y and z are order with respect to each reactant

Plot of log(rate) vs log[H2O2]/log[I-]/[log[H+] will give us values for x, y and z

When [H+] and [I-] are kept constant

we get another rate constant, known as pseudo-first oder rate constant also written as k'' which takes care of k as,

k'' = k[H+]^y.[I-]^z

rate law becomes, rate = k''[H2O2]

plot log(rate) vs log[H2O2]

log(rate) = log(H2O2) + logk'' as y = mx + c

we get a straight line with slope x and intercept log(k'')

With value of initial rate and [H2O2] initial concentration we may calculate k'' = rate/[H2O2]

Determine overall order or reaction x+y+z and calculate k for each reaction to calculate average

For standard deviation, take mean of k' values of individual runs and then carry out usual prod=cedure for calculation of standard deviation for k'