Question

For certain first-order reaction, 75% of the reaction complete in 30 min. How much time did it require to complete 99.9% of the reaction

Answer 1

∧ = 2.303\t multiply  log initial concentration /left concentration

t proportional to  log initial concentration /left concentration

t1 proportional to log 100/ 100-75

t2 proportional to log 100/100-99.9

t1/t2 = log 4/ log 1000

t1 = 30

calculating all value

t2 = 150 min