Question

An exacuted glass vessel weighs 50 g when empty, 148g when filled with an liquid of density o.989/cc and 50.5 g whenfilled with an ideal gas760 mmHg and at 300k. Determine the molecular weights of gss.​

Answer 1

MW of gas : 124.12 g/mol

Further explanation  

Density is a quantity derived from the mass and volume  

Density is the ratio of mass per unit volume  

With the same mass, the volume of objects that have a high density will be smaller than objects with a smaller type of density  

The unit of density can be expressed in g/cm³ or kg/m³  

Density formula:  

$\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}$

ρ = density  

m = mass  

v = volume  

glass vessel wieight = 50 g

glass vessel + liquid = 148 ⇒ liquid = 148 - 50 =98 g

volume of glass vessel :

$\tt V=\dfrac{m}{\rho}=\dfrac{98}{0.989}=99.1~ml$

An ideal gas :

m = 50.5 - 50 = 0.5 g

P = 760 mmHg = 1 atm

T = 300 K

$\tt PV=\dfrac{mass(m)}{MW}.RT\\\\MW=\dfrac{m.RT}{PV}\\\\Mw=\dfrac{0.5\times 0.082\times 300}{1\times 0.0991}=124.12~g/mol$