Question

the density of a mixture of O2 and N2 at NTP is 1.3g/litres. calculate partial pressure of O2.

Answer 1

$\huge\red{\boxed{\bold{Solutions}}}$

• Mol. Wt. of the mixture = density (g/L) × molar volume (L) $\implies$ 1.3 × 22.4 = 29.12.

$\large\underline\mathrm\red{Now,}$

Let the no. of moles of O2 and N2 be n1 and n2 respectively.

mol. Wt. of the mixture

=> 32n1 + 28n2 / n1 + n2.

32n1 + 28n2 / n1 + n2 = 29.12

$\large\underline\mathrm\red{Then,}$

We get me fraction of O2 = n1 / n1 + n2

= 0.28.

$\large\underline\mathrm\red{At \: NTP, }$

P = 1 atm.

Partial pressure of O2 = n1 / n1 + n2 × p = 0.28 × 1 = 0.28 atm.

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