Question

Rate of formation of SO₃ in the following reaction 2SO₂ + O₂ → 2SO₃ is 100 g min^–1. Hence rate of disappearance of O₂ is :

(A) 50 gmin^-1 

(B) 40 gmin^–1

(C) 200 gmin^–1 

(D) 20 gmin^–1

Answer 1

The correct answer is  D) 20 g/min 

Solution ::
$\frac{d}{dt}[S{O}_3]=100g/min$ 

$=\frac{100}{80}mole/min=1.25mole/min$ 

$\frac{-1}{2}\frac{d}{dt}[S{O}_2]$ 

$[S{O}_3]=\frac{-d}{dt}[O_2]=\frac{1}{2}\frac{d}{dt}$ 

$=\frac{1.25}{2}\times 32mole/min$ 

=20 g/min