1 cc of water becomes 1681 cc of steam when boiled at a pressure of `10^(5)Nm^(-2)`. The increasing internal energy of the system is
(Latent heat of steam is 540 cal `g^(-1)`, 1 cal = 4.2 J)

Options

A. 300 cal
B. 500 cal
C. 225 cal
D. 600 cal

Answer

B

Explanation

Initial volume of water `=V_(1)=1cm^(3)`
Volume of steam = `V_(2)=1681cm^(3)`
Changing in volume `dV=V_(2)-V_(1)=1681`
`=1680cm^(3)`
`=1680xx10^(-6)m^(3)`
Pressure `p=10^(5)N//m^(2)`
`dQ=mL=1xx540xx4.2`
`=22.68J`
`dW=pdV`
`=10^(5)xx1680xx10^(-6)=168`
Internal energy = `dU=2268-168=2100J`
= 500 cal