36) Calculate the volume of O₂ and volume of air needed for combustion of 1 kg carbon at STP:

37) 1.5 gm of CdCl₂ was found to contain 0.9 gm Cd. Calculate the atomic weight of Cd:

38) How many mL of perhydrol is required to produce sufficient oxygen which can be used to completely convert 2 L of SO₂ gas to SO₃ gas?

39) Oxidation number of sulphur in Na₂S₂O₃ is:

40) Equivalent weight of KMnO₄ in alkaline medium is equal to: (M = molar mass)