Question

18. An ideal gas is compressed from a volume of V 5.00 L to a Volume of V,- 3.00 L while in thermal contact with a heat reservoir of T 295 K. During the compression process the piston moves down a distance of d = 0.130 m under the action of an average external force of F = 25.0 KN. Find (a) the work done on the gas, (b) the change in internal energy of the gas, (c) the thermal energy exchange between the gas and the reservoir and (d) if the gas is thermally insulated so no thermal energy could be exchanged, what would happen to the temperature of the gas during the compression?

Answer 1

(a) Work done , W = force * distance

W = 25000 * 0.130

W = 3250 J

or

W = 3.25 kJ

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(b) As this is an Isothermal process

$\Delta$U = 0

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(c) Using first law of thermodynamics

Q = $\Delta$U - W

Q = - 3.25 kJ

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(d) The internal energy must increase and we know that internal energy is related to temperature directly, so temperature must increase.