What is the half-life (in seconds) of a zero-order reaction which has an initial reactant concentration of 0.884 M with a k value of 5.42 * 10-2 M/s?

Answer: 8.15s

Explanation:

1) A first order reaction is that whose rate is proportional to the concenration of the reactant:

r = k [N]

r = - d[N]/dt =

=> - d[N]/dt = k [N]

2) When you integrate you get:

N - No = - kt

3) Half life = > N = No / 2, t = t'

=> No - No / 2 = kt' = > No / 2 = kt' = > t' = (No/2) / k

3) Plug in the data given: No = 0.884M, and k = 5.42x10⁻²M/s

t' = (0.884M/2) / (5.42x10⁻²M/s) = 8.15s