Question

Question 5.19 A mixture of dihydrogen and dioxygen at one bar pressure contains 20% by weight of dihydrogen. Calculate the partial pressure of dihydrogen.

Class XI States of Matter Page 153

Answer 1

A mixture of H2 and O2 contains 20% by weight of H2 .

Let weight of mixture is 100g
then, weight of H2 = 20g
mole of H2 = given weight /molar weight
= 20/2 = 10 mol
weight of O2 = 80g
mole of O2 = given weight/molar weight
= 80/32 = 2.5 mol

now, mole fraction of H2 (x) = mole of H2/{mole of H2 +mole of O2}
= 10/(10 + 2.5)
= 10/12.5 = 0.8

now, parital pressure of H2 = mole fraction of H2 × total pressure

A/C to question,
total pressure = 1 bar

now, partial pressure = 0.8 × 1 = 0.8 bar

Answer 2

Here's the answer ⬆️

Hope it helps :)

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