Q13.3 Figure 13.8 shows plot of versus P for kg of oxygen gas at two different temperatures.
(a) What does the dotted plot signify?
(b) Which is true: ?
(c) What is the value of where the curves meet on the y-axis?
(d) If we obtained similar plots for kg of hydrogen, would we get the same
value of at the point where the curves meet on the y-axis? If not, what mass
of hydrogen yields the same value of (for low pressure high temperature
region of the plot) ? (Molecular mass of , of ,
.)
(a) The dotted plot corresponds to the ideal gas behaviour.
(b) We know the behaviour of a real gas tends close to that of ideal gas as its temperature increases and since the plot corresponding to temperature T1 is closer to the horizontal line that the one corresponding to T2 we conclude T1 is greater than T2.
(c) As per the ideal gas equation
The molar mass of oxygen = 32 g
R = 8.314
(d) If we obtained similar plots for kg of hydrogen we would not get the same
value of at the point where the curves meet on the y-axis as 1 g of Hydrogen would contain more moles than 1 g of Oxygen because of having smaller molar mass.
Molar Mass of Hydrogen M = 2 g
mass of hydrogen