70 calories of heat required to raise the temperature of 2 moles of an ideal gas at constant pressure from `30^@Cto 35^@C.` The amount of heat required (in calories) to raise the temperature of the same gas through the same range `(30^@C to 35^@C)` at constant volume is:

Options

A. 50 cal
B. 70 cal
C. 60 cal
D. 65 cal

Answer

A

Explanation

`dQ_(p)=nC_(p)dT`
`therefore C_(p)=(70)/(10)=7` cal/mol K
`C_(V)=C_(p)-R=7-2=5`
`dQ_(V)=nC_(V)dT=2xx5xx5=50cal`