A first order reaction is 20% complete in 10 minutes. Calculate the time taken for the reaction to go to 80% completion.
Answer & explanation
Correct answer: option 3
k = \(\frac{2.303}{t}\)log\(\frac{a}{a-x}\)
k = \(\frac{2.303}{10}\)log\(\frac{100}{100-20}\) = 0.0223 min-1
0.0223 = \(\frac{2.303}{t}\)log\(\frac{100}{100-80}\) = 72.18 min