The relative reactivity of 1°, 2°, 3°

Amount of mono-chlorinated products = No. of hydrogen reactivity

Mono-chlorinated products from 1° H = 9 1 = 9

Mono-chlorinated products from 2° H = 2 3.8 = 7.6

Mono-chlorinated products from 3° H = 1 5 = 5

Total mono-chlorinated products = 9+7.6+5 = 21.6

Yield % for 1° H chlorination = 9×100/21.6 = 41.67%

Yield % for 2° H chlorination = 7.6×100/21.6 = 35.18%

Yield % for 3° H chlorination = 5×100/21.6 = 23.15%