The specific heat of helium at constant volume is `12.6 Jmol^(-1)K^(-1).` The specific heat of helium at constant pressure in `Jmol^(-1)K^(-1)` is about
(Assume the temperature of the gas is moderate, universal gas constant, `R=8.314 J mol^(-1)K^(-1)`

Options

A. 12.6
B. 16.8
C. 18.9
D. 21

Answer

D

Explanation

Given, `C_(v)=12.6J mol^(-1)K^(-1)`
`R=8314J mol^(-1)K^(-1)`
The specific heat of helium at constant pressure, `C_(p)=C_(v)+R=12.6+8.314=21`