Question

The heat capacity at constant volume of a monoatomic gas is `35 j//K`. Find
(a) the number of moles
(b) the internal energy at `0^@ C`.
(c ) the molar heat capacity at constant pressure.

Answer 1

Correct Answer - A::B::C
(a) As discussed in the above problem,
`C_v = n C_V`
:. `n = (C_v)/(C_V) = (C_v)/((3//2)) R`
= `(35)/(1.5 xx 8.31) = 2.81`
(b) Internal energy,
`U = n (f/2 R T)`
`f = "degree of freedom" = 3`
`:. U = (2.81)(3/2)(8.31)(273)`
= `9562 J = 9.56 kJ`
( c) `C_p = (5)/(2) R = (5/2)(8.31)`
= `20.8 j//mol- K`.