(i) Balance each of the following chemical equations :

1. FeCl₃ + NH₄OH ⟶ NH₄Cl + Fe(OH)₃

2. Zinc + Nitric acid ⟶ Zinc nitrate + Nitrogen dioxide + Water

(ii) Identify the substance which matches the description given below:

1. White crystalline substance which sublimes on heating.
2. The metal that cannot displace hydrogen from dilute hydrochloric acid.

Define or explain the following terms :

(i) Absolute temperature

(ii) Valency

(iii) Ozone depletion

(iv) Electrovalent bond

(v) Atom

Name the kind of particles (ions or molecules) present in:

(i) Sodium chloride

(ii) Carbon tetrachloride

Draw the orbital structure of each of the following compounds:

(i) Water

(ii) Magnesium chloride

[At.No. : H = 1, 0 = 16, Mg = 12, Cl = 17]