Question

A gas cylinder holds 85 g of a gas ‘X’. The same cylinder when filled with hydrogen holds 8.5 g of hydrogen under the same conditions of temperature and pressure. Calculate the molecular weight of ‘X’.

August 1, 2024

Answer

Vapour density of gas X

= $Wt\ of\ certain\ volume\ of\ gas\ at\ STP\over Wt\ of\ same\ volume\ of\ H_2\ at\ STP$

= $85\over 8.5$

= 10

Molecular weight = 2 × Vapour density

= 2 × 10 = 20 g

Hence, molecular weight of gas X is 20 g

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