Question

What is meant by the following terms:
(a) Aqua fortis
(b) Aqua regia
(c) Fuming nitric acid
(d) Decrepitation

Answer 1

(a) Aqua fortis is the ancient name for nitric acid.
(b) Aqua regia is a mixture of concentrated nitric acid and concentrated hydrochloric acid, mixed together in the ratio of 1:3 by volume. This acid is capable of dissolving noble metals.
(c) Fuming nitric acid is a mixture of nitric acid and nitrogen dioxide. It is obtained by distilling nitric acid through a small amount of starch. Starch reduces nitric acid to nitrogen dioxide that dissolves in the remaining nitric acid to form fuming nitric acid, giving the acid a brownish colour.
(d) Decrepitation is the disintegration of a substance in which a cracking sound is produced when chemicals such as lead nitrate are heated.