Question

25 ml of O₂ contracts to 20 ml when subjected to silent electric discharge in an ozoniser. What further contraction would be observed if the partially ozonised oxygen is treated with oil of cinnamon (which absorbs ozone). All volumes are reported at the same temperature and pressure –

• A. 5 ml
• B. 20 ml
• C. 10 ml
• D. 15 ml

Answer 1

Answer: (C)

10 ml

Answer 2

3O₂ ¾® 2O₃

Before 25 0

Reaction

After 25 – x $\frac{2}{3}$x

Reaction

So 25 – x + $\frac{2}{3}$x = 20

̃ $\frac{x}{3}$ = 5 ̃ x = 15

So volume of O₃ produced = 10ml

So further contraction in volume = 10 ml