Background Nitrogen monoxide(No) is a colourless gas. It can be prepared by the reaction of sodium nitrite with acidified iron() sulphate solution 2NaNO2(s)+ 2FeSo4(aq)+3H2SO4(aq)- 2NO(g)+ Fe2(S04)3(aq)+2NaHSO4(aq)+2H,() Nitrogen monoxide is very reactive and is readily oxidised in air to produce nitrogen dioxide 2NO(g)+02(g) 2NO249)Background Nitrogen monoxide (NO) is a colourless gas. It can be prepared by the reaction of sodium nitrite with acidified iron(II) sulphate solution: Nitrogen monoxide is very reactive and is readily oxidised in air to produce nitrogen dioxide: