Question

Experiments have shown the following reaction to be zero order with a rate constant = 3.10 10-1 M/sec. A → B + 2 C If you started with [A] = 3.000 M, how many minutes until the concentration of A = 2.442 M? I already found the answer to this to be 0.03 minutes but cannot figure out the second part below How many minutes until the concentration of C reaches equals 1.674 M?

Answer 1

Ok then we know that for a zero order reaction the integrated law will be

[A] = [A]₀ -kt

ok then we have [A]₀ = 3.000 M and k= 3.10x10^-1 M/s

we know from the stequiometry of the reaction than

[A] / t = 1/2( C /t) = k (The rate of dissapereance of A = 1/c times the rate of appareance of C)

Now assuming that [C]₀= 0 then C = 1.647 M - 0 = 1.647 M

then k = 1/2 ( C /t)

Then we have  3.10x10^-1 M/s = 1/2 (1.647 M /t)

t = 3.10x10^-1 M/s * 2 / 1.647 M

t = 0.38 s