A heating coil is immersed in a 100 g sample `H_(2)O(l)` at 1 bar `100^(@)C` in a closed vessel. In this heating process, `60%` of the liquid is concerted in to gaseous form at constant pressure of 1 bar. Densities of liquid and gaseous water under these conditions are `1000kg//m^(3)` and `0.60kg//m^(3)` respectively. Magnitude of the work done for the process is :

Options

A. 4997 J
B. 4970 J
C. 9994J
D. 1060 J

Answer

C

Explanation

`w = -P_(ext)(V_(f)-V_(i))`
`= -10^(5) ((60 xx 10^(-3))/(0.60)+(40 xx 10^(-3))/(1000) - (100 xx 10^(-3))/(1000))`
`= -10^(5)(100 xx 10^(-3) + 0.04 xx 10^(-3) - 0.1 xx 10^(-3))`
`|w| = 9994 J`