Question

It was found that 380 mL of a gas at 27 and 800 mm of Hg weighed 0.455 g. Find the molecular weight of the gas.

Answer 1

volume=380 ml=0.380 liters

temperature= ${27}^{0}c=273+27=300K$

Now, using by formula

$PV=nRT$ (R= gas constant= $8.2\times {10}^2$

n=$\frac{pv}{RT}$=$\frac{1.052\times 0.380}{8.2\times {10}^2\times 300}$=0.0162

Now, given mass of the gass is 0.455

no of moles= $\frac{mass}{molarmass}$

molar mass=$\frac{mass}{noofmoles}$

$\frac{0.455}{0.0162}=28.08g/mole$