Van der waals,equation of state is(p+a/v²)(V-b)=nRT. The dimensions of a and b are
Options
(a) [ML³T²],[ML³T⁰]
(b) [ML⁵T⁻²],[M⁰L³T⁰]
(c) [M²LT²],[ML³T²]
(d) [ML²T],[ML²T²]
Correct Answer:
[ML⁵T⁻²],[M⁰L³T⁰]
Explanation:
((p+a/v²)(V-b)) / nT =R
Since we have (p+a/v²), the term a/v² needs to have units of pressure for subtraction to proceed.
Therefore, aV² = pressure
a = pressure x Volume²
=[ML⁻¹T⁻²] x (L³)²
=ML⁵T⁻²
In case of variable b, it should be same as volume as v-b should work.
b=(L³)