Question

the maximum number of molecules is present in 15 litre of H2 gas at STP 5 litre of N2 gas at STP 0.5 gram of H2 gas

Answer 1

The following concepts are key in answering this question :

1 mole of a gas at stp = 22.4 litres

1 mole of a gas at stp = 6.022 × 10²³ molecules

i) 15 litre hydrogen gas.

Moles = 15/22.4 = 0.6696 Moles

Molecules = 0.6696 × 6.022 × 10²³ = 4.0323 × 10²³ molecules

ii) 5 litres of Nitrogen gas

Moles = 5/22.4 = 0.2232 moles

Molecules = 0.2232 × 6.022 × 10²³ = 1.3441 × 10²³ molecules

iii) 0.5 grams hydrogen gas

Moles = mass /molar mass

= 0.5/2 = 0.25 moles

Molecules = 0.25 × 6.022 × 10²³ = 1.5055 × 10²³ molecules