The colourless vapours of a colourless liquid are pungent and bring tears in eyes on exposure. The yellowish green flame is resulted on burning vapours in $$\text{O}_2$$. In the presence of platinum catalyst the same reacts to give colourless gas which turns to reddish brown on explosive to air<br>(a) write balanced equations (b) calculate the volume of oxygen used separately for these reaction when 300 cc of vapour burn in $$\text{O}_2$$ at STP.

PLACEHOLDER ANSWER - the answer is equations and two volumes. The substance is ammonia. Burning in oxygen gives $$4\text{NH}_3 + 3\text{O}_2 \rightarrow 2\text{N}_2 + 6\text{H}_2\text{O}$$, and catalytic oxidation gives $$4\text{NH}_3 + 5\text{O}_2 \rightarrow 4\text{NO} + 6\text{H}_2\text{O}$$ (NO turns brown to $$\text{NO}_2$$ in air). For 300 cc of ammonia, burning uses $$\frac{3}{4} \times 300 = 225\text{ cc}$$ of $$\text{O}_2$$ and catalytic oxidation uses $$\frac{5}{4} \times 300 = 375\text{ cc}$$.