what is the unit of the constants in van der waal's equation?

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The Van der Waal's equation is given as follows

where p is the pressure of the gas, V is the volume, n are the number of moles of the gas, T is the temperature and R is the universal gas constant. The constant **'a'** is a measure of the magnitude of attractive forces between the molecules of a gas. Its unit is atm L^{2}mol^{−2}or bar L^{2}mol^{−2}. Larger the value of ‘*a*’, larger will be the intermolecular force of attraction. It is independent of pressure and temperature. The constant **'b'** is a measure of the effective size of gas molecules. Its unit is L mol^{−1}.

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