Question

Calculate the change in internal energy of `3 .0` mol of helium gas when its temperature is increased by `2. 0 K`.

Answer 1

Helium is a monoatomic gas.
Internal energy of n moles of the gas is ,
`U=3//2nRTthereforeDeltaU=3/2nR(DeltaT)`
Subsituting the values, `DeltaU=(3/2)(3)(8.31)(2.0)=74.8J`