For a real gas which obeys van der waals equation, a graph is obtained by plotting the values of `PV_(m)` along the y-axis and the values of P along the x-axis. What is the value of intercept on the y-axis of the graph?

Explanation

Plot of `PV_(m)` against P may give a graph like A or B. in both the cases, the graphs intersect the y-axis at P=0. Now at a very low pressure (i.e., `P to 0`), van der waals equation reduces to ideal gas equation.
`therefore PV=nRT`
or, `P((V)/(n))=RT`
or, `PV_(m)=RT`, [`V_(m)`=molar volume]
So, the value of intercept on the y-axis is RT.