Thermodynamics and Thermochemistry 1 Question 23

26. A piston filled with 0.04 mole of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 37.0C. As it does so, it absorbs 208 J of heat. The values of q and W for the process will be

(R=8.314 J/molK,ln7.5=2.01)

(2013 Main)

(a) q=+208 J,W=208 J

(b) q=208 J,W=208 J

(c) q=208 J,W=+208 J

(d) q=+208 J,W=+208 J

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Solution:

  1. The process is isothermal expansion, hence

q=W ΔE=0 W=2.303nRTlogV2V1 =2.303×0.04×8.314×310×log33550 =208 J q=+208 J W=208 J (expansion work)