Thermodynamics Question 219
Question: 540 calories of heat convert 1 cubic centimeter of water at $ 100^{o}C $ into 1671 cubic centimeter of steam at $ 100^{o}C $ at a pressure of one atmosphere. Then the work done against the atmospheric pressure is nearly
Options:
A) 540 cal
B) 40 cal
C) Zero cal
D) 500 cal
Show Answer
Answer:
Correct Answer: B
Solution:
Amount of heat given $ =540\ calories $ Change in volume $ \Delta V=1670\ c.c $
Atmospheric pressure $ P=1.01\times 10^{6}\ dyne/cm^{2} $
Work done against atmospheric pressure $ W=P\Delta V $
$ =\frac{1.01\times 10^{6}\times 1670}{4.2\times 10^{7}}\approx 40\ cal $
