Question

One-half mole of a monatomic ideal gas expands adiabatically and does 570 J of work. (a) By how many kelvins does its temperature change? (b) Specify whether the change is an increase or a decrease.

Answer 1

-98 K

Step-by-step explanation:

Given

`n=1/2=0.5\\W=570 J`

Given process is adiabatic and hence heat is zero. Thus change in internal energy is given by,

ΔU=Q-W

=0-570

=-570 J

Also for monoatomic gas change in internal energy is,

ΔU=3/2*n*R*ΔT

ΔT=-98

Since above answer has negative sign , which indicates temperature change is decrease.

Hence

The temperature change is approximately -98 K which is decrease.