Why is work zero in free expansion if volume changes?

[Apashanka]

If a gas is suddenly allowed to expand freely and adibatically inside a container then from the first law of thermodynamics dQ=0,
My question is whether the change of internal energy would be 0 and if it then how would the work done be 0 (since accessible volume of the gas changes inside the container changes)??
Thqnks

 

[Lord Jestocost]

Have a look at comment#2 in https://www.physicsforums.com/threads/free-expansion-of-gas.687051/#post-4355795

 

[Apashanka]

Have a look at comment#2 in https://www.physicsforums.com/threads/free-expansion-of-gas.687051/#post-4355795

Thanks that's clear now but temp remains constt for ideal gas but for real gas it decrease ,can you please help me in clearing this concept
Thank you

 

[DrClaude]

Thanks that's clear now but temp remains constt for ideal gas but for real gas it decrease ,can you please help me in clearing this concept
Thank you

For a real gas, you have to take into account the interaction between particles. In most cases, there is an overall attractive interaction (negative potential energy) which leads to a decrease in temperature when the gas expands and the attraction between the particle is globally lower because of the greater volume occupied. Note that this is not always true, as each gas has an inversion temperature above which the gas will heat upon expansion. This is already the case at room temperature and pressure for helium.