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 - A
According to the first law fo thermodynamics
`Delta U = q + w`
For isothermal reversible expansion of an ideal gas,
`Delta U = 0`
`:.q + w = 0`
Or `q = - w`
Since the system absorbs `208 J` of heat, we have
`q = + 208 J`
and `w = - 208 J`