Question

Consider the Van der Vaals equation of state: (????+????????????)(????−????)=???????????? where p is pressure, V is volume, n is number of moles, T is absolute temperature, R is the gas constant and a and b are constants. What are the dimensions of a and b?

Answer 1

Answer:

Units of a = $\frac{atm\ L^2}{mol^2}$

Units of b = $\frac{L}{mol}$

Explanation:

The Van der Waal's equation  is:-

$\left(P+\frac{an^2}{V^2}\right)\left(V-nb\right)=nRT$

Where,

P is the pressure

V is the volume

n is the number of moles

T is the temperature  

R is Gas constant having value

a and b are van der Waal's constant

If pressure is taken in atm and volume in L. So,

$P+\frac{an^2}{V^2}$ represents the pressure correction term. Then,

Units of a = $\frac{atm\ L^2}{mol^2}$

$V-nb$ represents the volume correction term. Then,

Units of b = $\frac{L}{mol}$