Question

An 8-L cylinder contains air at 300 kPa and 300 K. Now air is compressed isothermally to a volume of 2 L. The work done on air during this compression process is: (b) 1.8 kJ (c) 3.3 kJ (a) 119 kJ (d) 4.5 kJ

Answer 1

W=3.327 KJ

Step-by-step explanation:

Given that

`P_1=300 KPa,V_1=8 L`

`V_2=2 L`

Temperature remains constant it means that this is isothermal process

For isothermal process
`P_1V_1=P_2V_2`

We know that work for isothermal process

`W=P_1V_1\ln (P_1)/(P_2)`

`W=P_1V_1\ln (V_2)/(V_1)`

Now by putting the values

`W=300* 8* 10^(-3)\ln (2)/(8)`

W=-3.327 KJ

Negative sign indicates is process is compression

W=3.327 KJ

So our option C is right.