Let's assume that both He and Nā have ideal gas behavior.
Then we can use ideal gas law,
Ā
Ā Ā PV = nRT
Where, P is the pressure of gas, V is the volume,
n is moles of gas, R is universal gas constant and T is the temperature in
Kelvin.
TheĀ PĀ andĀ VĀ areĀ sameĀ for the
both gases.
R is a
constant.
The only variables are n and T.
Let's say temperature ofĀ HeĀ isĀ TāĀ and temperature ofĀ NāĀ isĀ Tā.
n = m/MĀ where n is
moles, m is mass and M is molar mass.
Molar mass of He is 4 g/mol and molar mass of Nā is 28 g/mol
Since mass (m)Ā of both gases are same,
Ā moles of He = m/4
Ā moles of Nā = m/28
Let's apply the ideal gas equation for both gases.
For He gas,
Ā PV = (m/4)RTā Ā Ā Ā Ā Ā Ā Ā (1)
For Nā gas,
Ā PV = (m/28)RTā Ā Ā Ā Ā Ā Ā Ā (2)
(1) = (2)
(m/4)RTā =
(m/28)RTāĀ
Ā
Ā Ā Ā Ā Tā/4
= Tā/28
Ā Ā Ā Ā Tā Ā Ā = Tā/7
Ā Ā Ā Ā Ā 7Tā Ā = Tā
Hence, the
temperature of Nā gas is higher by 7
times than the temperature of He gas.