VALUES OF LATENT HEAT AND SPECIFIC HEATS 
79 
(295) Latent Heat. r 2 = — T\ (vi — v 2 ) = 373 X 1657 X 
go a l 
27.2 X 3.1856 X 10 “ 5 = 535.5. 
Example 4. Ice to Water at 0° by Melting 
T 2 = 273 + 0 = 273. 
v 2 = 1.00 volume of 1 gram of water at 0°. 
v 3 = 1.09 volume of 1 gram of ice at 0°. 
v 2 — v 3 = — 0.09. 
— = 134.6 atmospheres. 
a 1 
(296) Latent Heat. r 3 =“~ • ^ (v 2 — v 3 ) = 273 X (— 0.09) 
(-134.6) X 3.1856 X 10 _u X 760 = 80.066. 
Example 5. Aqueous Vapor in Contact with Water at 100°. 
dr 2 
¿r=-°- 708 
cp 2 = 1.0300 
fdv 2 \ 
\dT) 
P = 760 mm. 
T = 373 
001 
dr 2 
r 2 
(318) cpi — cp 2 — Y ~ y 
r 2 
Vi - v 2 
r/SDA 
-1 
L\377p 
\dT)p] 
535.5 535.5 tA 
= - 0.708 - -373- + [4.931 - 
0.001] = - 0.5504 
Specific Heat. Cp\ = 1.0300 — 0.5490 = 0.4810. 
Example 6. Water in Contact with Ice at 0° 
'dv 2 
dr 3 
dT 
= 0.6400 
(H),- 
(319) Cp 2 
0.00006 = + 0.00011. 
Cp 2 = 1.0000 water at 0°. 
n . _dr 3 rs r 3 r /dv 2 \ _ fdv 3 \ -1 
Cp3 ~ dT~ T + v 2 - v 3 LKdTjp \dTj P J 
= 0.6400 
v 2 
80 80 
273 + (-0.09) 
[- 0.00006 - 
0.00011] 
= 0.6400 - 0.2930 + 0.1510 = 0.4980. 
Specific Heat. Cp 3 = 1.0000 - 0.4980 = 0.5020.