An ideal gas occuping a volume of `2 dm^(3)` and a pressure of 5 bar undergoes isothermal and irreversible expansion against external pressure of 1 bar. The final volume of the system and work involved in the process is

Options

A. `10 dm^(3), 1000J`
B. `8 dm^(3), -800J`
C. `10 dm^(3), -800J`
D. `10 m^(3), -1000 J`

Answer

C

Explanation

As the process irreversible `w= -P_("ext") (V_(2) - V_(1))`
`= -(10-2) = -8 " bar lt" = -800J` As the process is isothermal `P_(1)V_(1)= P_(2)V_(2)`