Question

Explain the hydrides of oxygen family under the following points?
(i) Name and formula
(ii) Thermal stability
(iii) Reducing property
(iv) Acidic property
(v) Covalent character.

Answer 1

(i) Name and formula
Name Formula
Water $H_{2}O$
Calcium hydroxide $Ca(OH{)}_2$
Hydrogen di-sulphide $H_{2}S$
Sulphuric acid $H_{2}S{O}_4$
(ii) Thermal stability: Thermal stability of hydrides decreases in class because size of atoms effected to the bond power. As well as size of atoms increases the bond power decreases.
$H_{2}O>H_{2}S>H_{2}Se>H_{2}Te$
(iii) Reducing property: Elements of the group have tendency to gain electrons. Their atomsform stable octet after gaining two electrons. They lose electron with difficulty. They form anion but not cation. This is because they have high eletronegativity. On moving down the group electronegativity decrease and metallic character increases.
(iv) Acidic property: $H_{2}S{O}_4$ is a strong and which is ionized in water in two steps
$H_{2}S{O}_4\rightleftharpoons H^{+}+HS{O}_4^{-}$
$HS{O}_4\rightleftharpoons H^{+}+S{O}_4^{2-}$
$H_{2}S{O}_4$ is the main hydride of the oxygen family and acidic properties of other hydrides are nearly similar to it to a extent [Except $H_{2}O$ neutral].
Hydrides of oxygen family have more acidic properties.
(v) Covalent character: Covalent character increases on going down the group and ionization property decreases.