Activity co-efficient is a measure of the

A. Departure from ideal solution behaviour

B. Departure of gas phase from idea] gas law

C. Vapour pressure of liquid

D. None of these

Answer: Option A

Solution(By Examveda Team)

Activity coefficient \[{{\gamma }_{i}}=\frac{{{\overset\frown{{{f}_{l}}}}^{real}}}{\overset\frown{{{f}_{l}}^{ld}}}\]
For an ideal solution activity coefficient $$= 1$$
And for real solution it tells about the departure from ideal solution by real solution like compressibility factor in case of gases.