A sample consisting of `1mol` of a mono-atomic perfect gas `(C_(V) = (3)/(2)R)` is taken through the cycle as shown.

`DeltaU` for the process` (1 rarr2)` is

Options

A. `0.00` J
B. `+3.40 xx 10^(3)` J
C. `-3.40` J
D. `-3.40 xx 10^(3)`J

Answer

B

Explanation

In expansion from state 1 to state 2
P = 1 atm
`V_(1) = 22.44 L`
`V_(2) = 44.88 L`
`C_(v) = 3/2 R`
`DeltaT = T_(2)-T_(1) = 546 - 273 = 273 K`
`therefore DeltaU = nC_(v) DeltaT = 1 xx 3/2 xx 8.314 xx 273 = 3.40 xx 10^(3) J`