34) K−40 is a naturally occurring radioactive isotope having natural abundance 0.012% of potassium isotopes. How many K−40 atoms do you ingest by drinking one cup of whole milk containing 370 mg K?

35) P and Q are two elements which form P₂Q₃ and PQ₂. If 0.15 mol of P₂Q₃ weighs 15.9 gm and 0.15 mol of PQ₂ weighs 9.3 gm, what are the atomic weights of P and Q respectively?

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?