Question

Compound A is used in the manufacture of opticals. A on heating gives B. B further heating to form C. A reacts with hydrochloric acid to give D. Identify A, B and C. Explain the reaction.

Answer 1

1. Compound (A) is borax, which is used in the manufacture of opticals. 

2. Borax (A) on heating to give borax glass (B). Borax glass on further heating to give sodium metaborate (C).

3. Borax (A) reacts with hydrochloride acid to give boric acid.

A	Borax	Na2B4O7.10H2O
B	Borax glass	Na2B4O7
C	Sodium glass	Na2BO2
D	Boric acid	H3BO3