A sample of 0.1 g of water at `100^(@)C` and normal pressure `(1.013 xx 10^(5) Nm^(-2))` requires 54 cal of heat energy to convert to steam at `100^(@)C`. If the volume of the steam produced is 167.1 cc, the change in internal energy of the sample, is

Options

A. 104.3 J
B. 208.7 J
C. 42.2 J
D. 84.5 J

Answer

B

Explanation

Using first law of thermodynamics, `Delta Q = Delta U + Delta W`
`rArr 54 xx 4.18 = Delta U + 1.013 xx 10^(5)(167.1 xx 10^(-6)-0)`
`rArr Delta U = 208.7J`