(i) [C]

(ii) [D]

(iii) [B]

(iv) [A]

Sol.

→ ; 12 g of Mg reacts with 8 g of O 2 to form 20 g of MgO.

⇒ 1.2 g of Mg reacts with 0.8 g of O 2 to form 2.0 g of MgO.

→ ; Cl 2 → Cl – + ClO 3 – ⇒ Cl → Cl

Oxidation state of Cl = 0 in Cl

Oxidation state of Cl in Cl – = – 1

Change in oxidation number = 1

Cl → ClO 3 – [ClO 3 – is chlorate ion]

Oxidation state of Cl in Cl = 0

Oxidation state of Cl in ClO 3 – = 5

⇒ Change in oxidation number = 5

Hence when Cl 2 → Cl – + ClO 3 – Net change in oxidation number is 6.

⇒ Equivalent weight of Cl 2 = of its molecular weight.

Hence Normality = 6 × Molarity

→ ; Density of solution refers to the mass of the solution which has volume equal to 1ml.

→ ; Strength of solution refers to amount of solute in 1000 ml solution.

Thus if 10000 x g of solute are present in 1000 ml.

⇒ 10 x g of solute are present in 1 ml solution.