Explanatory notes
… ammonia in the presence of a catalyst (platinum, iron, chromium, bismuth or manganese oxides, etc.). Alternatively, … (sulphuric or hydrochloric acids, nitrous fumes) are eliminated by distillation and hot air. Nitric acid is a … refining. (B) SULPHONITRIC ACIDS Sulphonitric acids are mixtures in definite proportions (e.g., equal parts) of …