50 % of a first order reaction completes in 20 minutes. What will be the time taken for 100% completion of the same reaction?
Answer & explanation
Correct answer: option 4
For first order reaction,
t1/2 = \(\frac{0.693}{k}\)
20 = \(\frac{0.693}{k}\)
k = \(\frac{0.693}{20}\) = 0.03465 s-1
t = \(\frac{2.303}{k}\)log\(\frac{a}{a-x}\)
t100% = \(\frac{2.303}{0.03465}\)log\(\frac{100}{0}\)
t100% = \(\frac{2.303}{0.03465}\)log∞
t100% = ∞ (infinite time)