The thermal decomposition of phosphine to phosphorus and hydrogen gas is a first order reaction, with a half-life of 35 s at 680$^\circ$C. Calculate the time required for 95% of phosphine to decompose.

Question

$\begin{array}{1 1} 151\;s \\ 302\;s \\ 255\;s \\ 454\;s \end{array}$