- #1

Banyans

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## Homework Statement

117 J of energy is supplied as heat to 2.00 moles of an ideal gas at constant

pressure, the temperature rises by 2.00 K. Calculate the molar heat capacity at

constant pressure C_p,m and the molar heat capacity at constant volume C_v,m

for the gas. Is the gas monatomic or diatomic?

## Homework Equations

PV = nRT

ΔQ = n Cp ΔT

## The Attempt at a Solution

ΔQ = 117 J

n = 2 moles

ΔT = 2 K

ΔQ = n Cp ΔT = n αR ΔT

Cp = ΔQ/ (nΔT) = 29.25 J/K mole

Cp/R = 3.52

For ideal gases equation of state is

PV = nRT,

and work performed by the gas in isobaric process is

dA = PdV = nRdT,

which means Cv = Cp - R = 2.52 R.

But I have no idea how to relate this information to work out if its diatomic or monatomic.