• # question_answer In a first-order reaction, the reacting substance has half-life period of 10 min. What fraction of the substance will be left after an hour the reaction has occurred? A) 1/6 of initial concentration       B) 1/64 of initial concentration C) 1/12 of initial concentration      D) 1/32 of initial concentration

${{t}_{1/2}}=10;$ Number of half-life $=\frac{60}{10}=6=$ half-life ${{C}_{t}}=\frac{{{C}_{0}}}{{{\left( 2 \right)}^{n}}}=\frac{{{C}_{0}}}{{{\left( 2 \right)}^{6}}}=\left( \frac{{{C}_{0}}}{64} \right)$