JAMB - Chemistry (1998 - No. 14)
Excess phosphorus was burnt in a gas jar and the residual gas passed successively over concentrated KOH solution and concentration H2SO4 before being collected in a flask. The gases collected are?
carbon (IV) oxide, nitrogen and the rare gases
nitrogen and the rare gases
carbon (IV) oxide, nitrogen (IV) oxide and the rare gases
carbon (IV) oxide
Explicació
So phosphorus will remove oxygen by forming P205, KOH will absorb water vapors, and sulfuric acid will react with carbon dioxide thus removing it from the mixture. So nitrogen and rare gases will be left