question on partial pressure? 11th standard?

Question

The density of a mixture of O2 and N2 at stp is 1.3 g/litre. calculate the partial pressure of O2. Answer in atmospheres.
wats? the value of 1atmosphere in terms of height of mercury.

Answer 1

d= 1.3g/L

assume 22.4L of gas mixture so we deal with 1 mole of gas

mass = (1.3g/L)(22.4L) = 29.12g mixture

molar mass of gas mixture = 29.12g/mol

let x = % O2
then 1-x = % N2

molar mass O2 = 32.00g/mol
molar mass N2 = 28.02 g/mol

x(32.00g/mol) + (1-x)(28.02g/mol)=29.12g/mol
solve for x
divide eq by g/mol
32.00x + 28.02 - 28.02x -= 29.12
3.98x = 1.1
x = 1.1/3.98 = 0.2764
1-x = 0.7236

27.64% O2
72.36% N2

1atm = 760mmHg = 760torr = 101.325KPa

Answer 2

hfshaw didn t convert the a hundred and sixty.5 ok/Kmol to kJ to stick to contained interior the equation: dG1 = 177.8*10^3 J/mol - (298.15 ok)*a hundred and sixty.5J/(mol*ok) so i've got not got faith hfshaw s answer is effective. particularly, the equation could desire to be: dG1 = 177.8*10^3 J/mol - (298.15 ok)*0.1605kJ/(mol*ok)