Balance the following important equations :

1. NaHCO₃ + H₂SO₄ ⟶ Na₂SO₄ + H₂O + CO₂

2. NaOH + H₂SO₄ ⟶ Na₂SO₄ + H₂O

3. Pb(NO₃)₂ + NaCl ⟶ NaNO₃ + PbCl₂

4. FeSO₄ + NaOH ⟶ Na₂SO₄ + Fe(OH)₂

5. FeCl₃ + NaOH ⟶ NaCl + Fe(OH)₃

6. CuSO₄ + NaOH ⟶ Na₂SO₄ + Cu(OH)₂

7. FeCl₃ + NH₄OH ⟶ NH₄Cl + Fe(OH)₃

8. ZnO + NaOH ⟶ Na₂ZnO₂ + H₂O

9. Pb(OH)₂ + NaOH ⟶ Na₂PbO₂ + H₂O

10. Al₂O₃.2H₂O + NaOH ⟶ NaAlO₂ + H₂O

11. NaAlO₂ + H₂O ⟶ NaOH + Al(OH)₃

12. Al(OH)₃ ⟶ Al₂O₃ + H₂O

13. ZnS + O₂ ⟶ ZnO + SO₂

14. Fe₂O₃ + Al ⟶ Al₂O₃ + Fe

15. Al + Cl₂ ⟶ AlCl₃

16. NaCl + H₂SO₄ ⟶ Na₂SO₄ + HCl

17. Fe + HCl ⟶ FeCl₂ + H₂

18. Na₂CO₃ + HCl ⟶ NaCl + H₂O + CO₂

19. Pb(NO₃)₂ + HCl ⟶ PbCl₂ + HNO₃

20. AgCl + NH₄OH ⟶ Ag(NH₃)₂Cl + H₂O

21. MnO₂ + HCl ⟶ MnCl₂ + H₂O + Cl₂

22. Pb₃O₄ + HCl ⟶ PbCl₂ + H₂O + Cl₂

23. KMnO₄ + HCl ⟶ KCl + MnCl₂ + H₂O + Cl₂

24. K₂Cr₂O₇ + HCl ⟶ KCl + CrCl₃ + H₂O + Cl₂

25. NH₄Cl + Ca(OH)₂ ⟶ CaCl₂ + H₂O + NH₃

26. (NH₄)₂SO₄ + NaOH ⟶ Na₂SO₄ + H₂O + NH₃

27. Mg₃N₂ + H₂O ⟶ Mg(OH)₂ + NH₃

28. AlN + H₂O ⟶ Al(OH)₃ + NH₃

29. NH₃ + O₂ ⟶ N₂ + H₂O [burning of NH₃]

30. NH₃ + O₂ ⟶ NO + H₂O [Catalytic oxidation of NH₃]

31. NH₄OH + H₂SO₄ ⟶ (NH₄)₂SO₄ + H₂O

32. NH₃ + CuO ⟶ Cu + H₂O + N₂

33. NH₃ + Cl₂ ⟶ HCl + NCl₃ [nitrogen trichloride]

34. HNO₃ ⟶ H₂O + NO₂ + O₂

35. Ca(HCO₃)₂ + HNO₃ ⟶ Ca(NO₃)₂ + H₂O + CO₂

36. C + HNO₃ [conc.] ⟶ CO₂ + H₂O + NO₂

37. S + HNO₃ [conc.] ⟶ H₂SO₄ + H₂O + NO₂

38. Cu + HNO₃ [conc.] ⟶ Cu(NO₃)₂ + H₂O + NO₂

39. C + H₂SO₄ [conc.] ⟶ CO₂ + H₂O + SO₂

40. S + H₂SO₄ [conc.] ⟶ SO₂ + H₂O

41. Cu + H₂SO₄ [conc.] ⟶ CuSO₄ + H₂O + SO₂

Give balanced equations for (1) & (2) by partial equation method, [steps are given below]

1. Reaction of excess ammonia with chlorine – Ammonia as a reducing agent
   (a) Ammonia first reacts with chlorine to give hydrogen chloride and nitrogen.
   (b) Hydrogen chloride then further reacts with excess ammonia to give ammonium chloride.
2. Oxidation of Lead [II] Sulphide by Ozone
   (a) Ozone first decomposes to give molecular oxygen & nascent oxygen.
   (b) Nascent oxygen then oxidizes lead [II] sulphide to lead [II] sulphate.

Calculate relative molecular mass of

(a) ZnCO₃
(b) CaSO₄

[Zn = 65, S = 32, O = 16, Ca = 40, C = 12]

Calculate the percentage composition of

(a) calcium chloride
(b) calcium nitrate

[Ca = 40 , Cl = 35.5 , N = 14 , O = 16]