Question 1 Report
(a) What is meant by the term acid salt? Give one example.
(b) State the reason why an all-glass apparatus must be used for the laboratory preparation of concentrated trioxonitrate (V) acid.
(a) Acid salt
An acid salt is a salt formed by the partial replacement of the ionizable (replaceable) hydrogen atoms of a polybasic acid by a metal or ammonium ion, so it still contains replaceable hydrogen. Example: sodium hydrogen tetraoxosulphate(VI), NaHSO4 (sodium hydrogen carbonate, NaHCO3, is also acceptable).
(b) Why an all-glass apparatus is used
Concentrated trioxonitrate(V) acid, and its hot vapour, is a strong, corrosive oxidizing agent that attacks and corrodes rubber, cork and metal connections. Glass is chemically unreactive towards the acid, so an all-glass apparatus prevents corrosion, leakage and contamination of the acid.
Everything you need to excel in your exams