`1 mol` of `NH_(3)` gas at `27^(@)C` is expanded under adiabatic condition to make volume `8` times `(gamma=1.33)`. Final temperature and work done, respectively, are

Options

A. `150 K, 900 cal`
B. `150 K, 400 cal`
C. `250 K, 1000 cal`
D. `200 K, 800 cal`

Answer

A

Explanation

`T_2 = T_1 ((V_1)/(V_2))^(gamma -1) = 150 K`
`w = -C_V Delta T = - C_V(T_2 -T_1)`
=`-3 xx 2 xx (150 - 300) = 900 cal`.