Question

A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, what fraction of excess reagent is converted into product?

(a) 0.23

(b) 0.55

(c) 0.74

(d) 0.87

Answer 1

Correct option is (b) 0.55

The best explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. => The excess reagent is SO2, => fraction of SO2 converted into product = E/0.75F = 12.5/(0.75*30) = 0.55.