8. Give reasons for the following:
(a) Sulphuric acid forms two types of salts with NaOH,
(b) A piece of wood becomes black when concentrated
sulphuric acid is poured on it,
(c) Brisk effervescence is seen when oil of vitriol is
added to sodium carbonate.
Answers
Explanation:
1. In first reaction, only one equivalent of caustic soda(NaOH) is reacting with sulphuric acid which gives monosubstituted salt, while in second reaction, two equivalents of caustic soda react with sulphuric acid to give disubstituted salt. Thus alkali metals give 2 kind of salts with
2.Wood is composed of cellulose , (C6H10O5)n . When concentrated sulphuric acid is poured on wood , the wood will get charred because of the dehydration and result in the formation of carbon. Due to this , a black mass of carbon will be formed.
3.when oil of vitriol is added to sodium carbonate BRISK EFFERVESCENCE is seen because of release of Co₂ gas during the reaction. OIL OF VITRIOL -Oil of vitriol is the other name of sulfuric acid . It is a mineral acid made up of three component i.e, sulfur , hydrogen , oxygen .