Question

A gas is enclosed in a cylinder fitted with a light frictionless piston and maintained at atmospheric pressure. When 254 kcal of heat is added to the gas, the volume is observed to increase slowly from 12.0 m3 to 16.2 m3 .
Part A: Calculate the work done by the gas. Express your answer with the appropriate units.

Part B: Calculate the change in internal energy of the gas, Express your answer with the appropriate units.

Answer 1

Answer:

(A) The work done by the gas is 425,565 Joules

(B) The change in internal energy of the gas is 637,171 Joules

Explanation:

(A) W = P(V2 - V1)

P = 1 atm = 101325 N/m^2

V2 = 16.2 m^3

V1 = 12 m^3

W = 101325(16.2 - 12) = 101325 × 4.2 = 425,565 Joules

(B) ∆U = Q - W

Q = 254 kcal = 254×4184 = 1,062,736 Joules

∆U = 1,062,736 - 425,565 = 637,171 Joules