(a) Name the gas evolved when dilute hydrochloric acid is added to each of the following solids and the mixture is warmed (i) sodium trioxocarbonate (IV); (ii) potassium trioxosulphate (IV); (iii) iron (II) sulphide.
(b) Name the reagent(s) that you would use to identify the gas in (a)(ii) above.
Explanation
(a)(i) Carbon(IV) oxide is evolved. (ii) Sulphur (V) oxide is evolved. (iii) Hydrogen sulphide is evolved. (b) Sulphur (IV) oxide turns potassium tetraoxomanganate (VII) solution colourless without any precipitation. Sulphuric (IV) oxide turns acidified potassium heptaoxodichromate (IV) solution from golden yellow to green.
