for 
of oxygen gas at two different temperatures.
(a) What is the value of PV/T where the curves meet on the 
-axis?
(b) If we obtained similar plots for 
kg of hydrogen, would we get the same value of PV/T at the point where the curves meet on the y-axis? If not, what mass of hydrogen yields the same value of PV/T (for low pressure high temperature region of the plot)? (Molecular mass of 
, of 
Solution:
(a) We will use 
Mass of the gas is given as 
Molecular mass of 
is given as 
So,
Number of mole 
given weight / molecular weight
So, 
So,
Value of 
(b) 
of 
does not represent the same number of mole.
For Example, molecular mass of is 
So, number of moles of require is 
Therefore,
Mass of required = no. of mole of 
molecular mass of
As a result, 
of would yield the same value