Question

A gas cylinder contains 24 × 10²⁴ molecules of nitrogen gas. If Avogadro's number is 6 × 10²³ and the relative atomic mass of nitrogen is 14, calculate the mass of nitrogen gas in the cylinder.

Answer 1

Nitrogen exists as N₂.

Hence its molecular mass = 14 × 2 = 28 g

6 × 10²³ molecules of nitrogen weigh = 28 g

24 × 10²⁴ molecule of nitrogen will weigh = `28/(6 xx 10^23) xx 24 xx 10^24`

= 28 × 4 × 10

= 1120 g