The molar specific heat of oxygen at constant pressure `C_(P) = 7.03 cal//mol .^(@)C` and `R = 8.31 J//mol .^(@)C`. The amount of heat taken by 5 mol of oxygen when heated at constant volume from `10^(@)C` to `20^(@)C` will be approximately.

Options

A. 25 cal
B. 50 cal
C. 250 cal
D. 500 cal

Answer

C

Explanation

c. `Q = nC_(v) Delta T = n (C_(P) - R) Delta T`
`= 5 (7.03 - (8.31)/(4.2)) xx (20 - 10) = 250 cal`