Piston cylinder device initially contains `0.5m^(3)` of nitrogen gas at `400 kPa` and `27^(@)C`. An electric heater within the device is turned on and is allowed to apss a current of `2 A` for `5 mi n` from a `120 V` source. Nitrogen expands at constant pressure and a heat loss of `2800 J` occurs during the process.
`R=25//3 kJ //k mol - K`
Number of moles of nitrogen gas is

Options

A. `0.8 k mol`
B. `0.08 k mol`
C. `0.8 mol`
D. `0.08 mol`

Answer

B

Explanation

Number of moles of nitrogen gas
`n=(PV)/( RT)=((40kPa)(0.5m^(3)))/(((25)/(3)kJ//k mol-K)(300K))=0.08 k mol`