NEET Class neet Answered

1 L-Bar = 100 J

The temperature of the gas, T= 300 K

Initial volume, V1= 0.1 L

Final volume, V2 = 0.25 L

External pressure, P = 2 bar

Work done by the gas, W = ?

A gas expanding against a constant external pressure is an irreversible process.

The work is done in an irreversible process.

W = -PΔV

W = - P (V2 - V1)

Here,

W is the work done.

P is the pressure.

V is the volume.

The negative (-) sign indicates the system loses energy.

By substituting the given values in the above formula, we get

W = -2 Bar (0.25 L – 0.1 L)

     = -2 ⨯ 0.15 L Bar

     = -0.30 L Bar (1 L Bar = 100 J)

     = - 0.30 ⨯ 100 J

    = -30 J