(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.