Question

Calculate the half-life of the first order reaction $C_2{H}_4{O}_2\left(g\right)⟶C{H}_4\left(g\right)+C{O}_2\left(g\right)$ if the initial pressure of $C_2{H}_{4}O\left(g\right)$ is $84$ mm and the total pressure at the end of $16$ min is $110$mm.

• A. $40$min
• B. $120$min
• C. $43.31$min
• D. $80$min

Answer 1

Answer: (C)

$43.31$min

$k=\frac{2.303}{t}log\frac{p_1}{p_2}$

$k=\frac{2.303}{16}log\frac{84}{110}$

$k=0.01685{min}^{-1}$

$t_{1/2}=\frac{0.693}{k}$

$t_{1/2}=43.31min$