Suppose the initial amount of N2O5 in an experiment is 64 g. What mass (g) remains after four half-lives?

Question

N2O5(g)     2 NO2(g)  +  ½ O2(g)

 

N2O5 decomposes by a first-order reaction.  Suppose the initial amount of N2O5 in an experiment is 64 g.  What mass (g) remains after four half-lives?

Answer 1

What is the rate of reaction, or at least the rate constant for this reaction.

Assuming it is a first order rate with respect to N2O5, the t_1/2 will be 0.693/k but we must know k, or at least be able to calculate it from kinetic data As posed, the question can't be answered.