Question

A cylinder contains 68g of ammonia gas at STP

1. What is the volume occupied by this gas?
2. How many moles of ammonia are present in the cylinder?
3. How many molecules of ammonia are present in the cylinder? [N - 14, H - 1]

Answer 1

(i) Molecular gram atom wt. of NH₃ = 17 gm

17 gm of NH₃ has volume at STP = 22.4 litres

68 gm of NH₃ has volume at STP = `(22.4 xx 68)/17`

= 89.6 litres

(ii) No. of moles in 68 gm of NH₃ = `68/17`

= 4 moles

(iii) No. of molecules of ammonia = 4 × 6.023 × 10²³

= 24.092 × 10²³