Question

A piston filled with `0.04` mole of an ideal gas expands reversible from `50.0mL` at a constant temperature of `37.0^(@)C` . As it does so, it absorbs `208J` of heat. The value of `q` and `W` for the process will be `(R=8.314J//molK` , `1n7.5=2.01)`
A. `q=+208 J`, `w=+208 J`
B. `q=208 J`, `w=-208 J`
C. `q=-208 J`, `w=-208 J`
D. `q=-208 J`, `w=+208 J`

Answer 1

Correct Answer - B
For isothermal expansion of an ideal gas, `DeltaV=0`
Hence, from first law of thermodynamics,
`DeltaU=q+w`, we have `q=-w`. A process involves adsoption of heat, i.e., it is endothermic `:. Q=-208 J`. Hence `w=-208 J`