Cylinder of Ideal Gas with a Piston?

Question

A cylinder contains 0.250 mol of carbon dioxide gas at a temperature of 27.0 C. The cylinder is provided with a frictionless piston, which maintains a constant pressure of 1.00 atm on the gas. The gas is heated until its temperature increases to 127.0 C. Assume that the CO_2 may be treated as an ideal gas.

A) How much work W is done by the gas in this process?

B) What is the change in internal energy Delta U of the gas?

C) How much heat Q was supplied to the gas?

anil bakshi · Accepted Answer

heat supplied to gas at constant pressure
work done by gas dW = P dV ---(1)
gas equation PV = n RT >>> differentiating
P dV + v dP = n R dT
P dV + v (0) = n R dT [ dP = 0 as p = const]
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dW = P dV = n R dT = 0.250 * 8.3*[127 - 27]
dW = 207.5 joules
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B) change in internal energy dU = n Cp dT
dU = 0.25 * Cp * 100 = joules
look for the CP = sp heat of Co2 and plug in
====================
c) heat supplied dQ, by 1st law, is
dQ = dU + dW
put values from (a) and (b)

Cylinder of Ideal Gas with a Piston?

1 Answer