Question

A ceratin compound (A) imperts a golden yellow flame and exhibits following reactions:
a. When a concentrated solution of (A) is boiled with Zn power, hydrogen gas is evolved.
b. When an aqueous solution of (A) is added to an precipitate is obtained, which dissolves in excess of solution (A).
Identify (A) and give equations for reactions in (ii).

Answer 1

a. `underset((A))(NaOH_((aq)))+Zn rarr underset("zincate")underset("Sodium")(Na_(2)ZnO_(2(aq)))+underset("gas")underset("Hydrigon")(H_(2)uarr)`
b. `underset((A))(NaOH_((aq)))+underset("chloride")underset("Stannous")(SnCI_(2))rarrunderset("White ppt".)(Sn(OH)_(2)darr) + 2NaCI`
`Sn(OH)_(2)+NaOH rarr underset("Solulble")(Na_(2)SnO_(2))+2H_(2)O`
Hence, (A) is NaOH and imparts golden yellow colour to the flame.