The internal energy of 3 moles of hydrogen at temperature T is equal to the internal energy of n moles of helium at temperature The value of n is (assume hydrogen and helium to behave like ideal gases)
5
10
6
The internal energy of n moles of an ideal gas at temperature T is given by
Where f= number of degrees of freedom
For hydrogen, f = 5. Therefore
For helium, f = 3. Therefore
Which gives n = 10