Question

99% of a first order reaction was completed in 32min. When will 99.9% of the reaction complete ?

• A. 50 min
• B. 46 min
• C. 49 min
• D. 48 min

Answer 1

Answer: (D)

48 min

Answer 2

$k =\frac{2.303}{t} \log \frac{100}{100-x}$ Substituting the values, $k=\frac{2.303}{32} \log \frac{100}{1}$ $k = 0 . 1 4 4 \min ^{-1}$ $t=\frac{2.303}{0.144} \log \frac{100}{0.1}$ $t = 4 8 ~ m i n$