State the type of reactions each of the following represent and balance the ones that are not balanced.

(a) Cl₂ + 2KBr ⟶ 2KCl + Br₂

(b) NaOH + HCl ⟶ NaCl + H₂O

(c) 2HgO ⟶ 2Hg + O₂ ↑

(d) Fe + CuSO₄ ⟶ FeSO₄ + Cu

(e) PbO₂ + SO₂ ⟶ PbSO₄

(f) 2KClO₃ ⟶ 2KCl + 3O₂ ↑

(g) 2H₂O₂ ⟶ 2H₂O + O₂ ↑

(h) KNO₃ + H₂SO₄ ⟶ HNO₃ + KHSO₄

(i) CuO + H₂ ⟶ Cu + H₂O

(j) CaCO₃ ⟶ CaO + CO₂ ↑

(k) NH₄Cl ⟶ NH₃ + HCl

(l) PbO + 2HNO₃ ⟶ Pb(NO₃)₂ + 2H₂O

(m) AgNO₃ + NaCl ⟶ AgCl ↓ + NaNO₃

Which of the of following is not a chemical change.

1. Rusting of iron
2. Iron is magnetised
3. Potassium is dissolved in water
4. Magnesium wire is burnt

Burning of a metal is an example of :

1. Decomposition reaction
2. Combination reaction between an element and a compound
3. Direct combination reaction between two elements
4. Displacement reaction

Formation of white precipitate on mixing sodium chloride solution and silver nitrate solution is an example of …………… reaction.

1. Combination
2. Decomposition
3. Displacement
4. Double decomposition