How do I find the half life if I was given that Solution A1

How do I find the half life if I was given that Solution A1 (0.008 M) took 261.6 seconds to change color and Solution B1 (0.04 M) took 388.8 seconds to change color and the average temperature was 55.5 C? Then my experient data shows: Initial T / Final T / Initial time / Final time / Half-Life So what would my half life calculations be using the data below? Run 1 85C / 84.5 / 0 / 0:54:97 _____ (thats 0 minutes, 54 seconds, 97 milliseconds) Run 2 75C / 72.0 / 0 / 1:32:78 _____ Run 3 65.2C / 63.5 / 0 / 3:12:22 _____ Run 4 45.2C / 47.0 / 0 / 29:55:97 _____ Run 5 55.0 C and my lab says that the half life for run 5 is the average of the two half lives (A1 and B1) so what would that be? Using the data above what would be: t1/2, k, ln k, 1/T Run 1 357.9K _____ _____ _____ _____ Run 2 346.65K _____ _____ _____ _____ Run 3 337.4K _____ _____ _____ _____ Run 4 319.15K _____ _____ _____ _____ Run 5 328.15K _____ _____ _____ _____ And after I find that for all 5 runs, how do I find the EA? #2 Whats the order of increasing ability to catalyze the decomposition of H2O2? ____ < _______ < _______ (KI, FeCl1, bovine catalase) Note: please explain how you get the answers (briefly

Solution

Definition and Formula

By definition, half-life is the period of time it takes for a substance undergoing decay to decrease by half. An exponential decay process can be described by any of the following three equivalent formulas:

N_t = N₀(1/2)^t/t_1/2
N_t = N₀e^-t/
N_t = N₀e^-t

where
N₀ is the initial quantity
N_t is the quantity that still remains after a time t,
t_1/2 is the half-life
is the mean lifetime
is the decay constant

t_1/2 = ln(2) = ln(2)/