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Physical Chemistry

Language of Chemistry Stoichiometry Atomic Structure Oxidation and Reduction Periodic Table Acid and Base Electronic Theory of Valency Equivalent Weight and Atomic Weight

Physical Chemistry-II

Non-Metals

Inorganic Chemistry

Introduction Compound of Metals Hydroxide Chlorides And Nitrates Sulphates And Carbonates General Metallurgy Sodium and Its Compounds Copper Zinc Iron

Compound of Metals

Oxides:

Preparation:

By direct combination of metal and oxygen:

-Almost all metal oxides can be prepared by this method.

$2 C a + O_{2} \to 2 C a O$

$2 Z n + O_{2} \to 2 Z n O$

$4 N a + O_{2} \to 2 N a_{2} O$

$2 C u + O_{2} \to 2 C u O$

By decomposition of carbonates, sulphates, nitrates

$Z n C O_{3} \to Z n O + C O_{2}$

$2 Z n S O_{4} \to 2 Z n O + 2 S O_{2} + O_{2}$

$2 Z n (N O_{3})_{2} \to 2 Z n O + 4 N O_{2} + O_{2}$

Roasting of Sulphide ore:

$P b S + 2 O_{2} \to 2 P b O + S O_{2}$

$H g S + 2 O_{2} \to 2 H g O + S O_{2}$

Metal with hot water or steam

$M g + H_{2} O \to M g O + H_{2}$

$Z n + H_{2} O \to Z n O + H_{2}$

$2 A l + 3 H_{2} O \to A l_{2} O_{3} + 3 H_{2}$

Properties:

Solubility:

-Alkali oxide are soluble in water except $L i_{2} O$ which is partially soluble in water.

-Alkaline earth metal oxides are sparingly soluble in water.

-Other oxides are insoluble in water.

Action of heat:

-Almost all metal oxides are thermally stable except $H g O$ and $A g_{2} O$

$2 H g O \to 2 H g + O_{2}$

$2 A g_{2} O \to 4 A g + O_{2}$

Types of oxides:

Basic Oxide:

-Reacts with acid to form salt and water.

-They are metallic oxides.

-Eg: $M g O, C u O, F e O, F e 2 O 3$ , etc.

$N a_{2} O + 2 H Cl \to N a Cl + H_{2} O$

-They changes red litmus paper to blue.

Acidic Oxides:

-Reacts with base to form salt and water.

-They are non-metallic oxides.

-Eg: $S O_{2}, S O_{3}, P_{2} O_{3}, S i O_{2}, N O_{2}$

$C O_{2} + 2 N a O H \to N a_{2} C O_{3} + H_{2} O$

-They changes blue litmus to red

Neutral Oxide:

-Shows neither acidic nor basic character.

-Neutral towards litmus test.

-Eg: $CO, H_{2} O, NO, N_{2} O,$ etc.

Amphoteric Oxide:

-It is metallic oxide of few metals, which can show both acidic and basic properties.

-Reacts with both strong acid and alkali to produce salt and water.

-Eg: $Z n O, A l_{2} O_{3}, P b O, A s_{2} O_{3}, B e O,$ etc.

$Z n O + H_{2} S O_{4} \to Z n S O_{4} + H_{2} O$

$Z n O + 2 N a O H \to N a_{2} Z n O_{2} + H_{2} O$

$A l_{2} O_{3} + 2 N a O H \to 2 N a A l O_{2} + H_{2} O$

$A l_{2} O_{3} + 6 H Cl \to 2 A lC l_{3} + 3 H_{2} O$

Peroxide and Superoxide:

Peroxide:

-Treated with dil. acid to yield $H_{2} O_{2}$ .

-Oxidation state of oxygen on peroxide is $- 1$ .

-Eg: $B a O_{2}, K_{2} O_{2}, N a_{2} O_{2},$ etc.

$N a_{2} O_{2} + d i l . H_{2} S O_{4} \to N a_{2} S O_{4} + H_{2} O_{2}$

Superoxide:

-Treated with dil. acid to yield $H_{2} O_{2}$ and $O_{2}$ .

-Oxidation state of oxygen on superoxide is $- 1/2$ .

-Eg: $K O_{2}, R b O_{2}, C s O_{2},$ etc.

$2 K O_{2} + H Cl \to 2 K Cl + H_{2} O_{2} + O_{2}$

Mixed Oxides:

-Oxides which are the mixture of two or more oxides.

-Eg: $F e_{3} O_{4}, P b_{3} O_{4}, M n_{3} O_{4},$ etc

- $F e_{3} O_{4}$ is the mixture of $F e O$ and $F e_{2} O_{3} .$

Sub-Oxide:

-Contain lesser number of oxygen than required according to valency.

-Eg: $C 3 O 2 (O = C = C = C = O)$ , $A g_{4} O_{2}$ etc.