NEET2024ChemistryThermodynamics (C)Actual
Choose the correct statement for the work done in the expansion and heat absorbed or released when 5 litres of an ideal gas at 10 atmospheric pressure isothermally expands into vacuum until volume is 15 litres:
Options
- ABoth the heat and work done will be greater than zero
- BHeat absorbed will be|less than zero and work done will be positive
- CWork done will be zero and heat will also be zero
- DWork done will be greater than zero and heat will remain zero
Correct answer
C. Work done will be zero and heat will also be zero
Step-by-step solution
Since it is isothermal, T =0 U = nC C _ v T =0 Since expansion is taking place against vacuum P_ ext =0W=-P ex V=0 From first law of thermodynamics, U=q+W0=q+0q=0