(a) Which compound of sodium is used for softening hard water?
(b) What is the effect of heat on the compounds ? (Write equations for the reactions):
(c ) Draw the structure of :
(i) `BeCI_(2)` (in vapour state)
(ii) `BeCI_(2)` (in solid state)

Explanation

(a) Sodium hydrogen carbonate `(NaHCO_(3))` is used for softening hard water.
(b) `underset(("Glysum"))(CaCO_(2)) overset("Heat")(to) CaO + CO_(2)`
(ii) `underset(("Glysum"))(CaSO_(4).2H_(2)O) overset("Heat")(to) underset(("Plaster of pairs"))(CaSO_(4).1//22H_(2)O) + 3//2 H_(2)O`
(c ) For answer, consult section 10.14