Temp.

Pressure in mm.

0°

12.0

5

17.0

10

23.5

15

32.2

20

43.8

25

59.0

30

78.6

35

103.6

40

134.9

45

174.0

50

222.2

Temp.

Pressure in mm.

55°

281.2

60

352.7

65

438.9

70

542.5

75

666.0

80

812.7

85

985.2

90

1187.0

95

1422.0

100

1694.0

105

2007.0

The following data, giving vapour pressure and heat of vaporisation at various temperatures up to the critical temperature, are due to Young.3

1 Compt. rend., 1883, 96, 1140, 1225. 2 Ber., 1899, 32, 1818.

3 Scient. Proc. Roy. Dublin Soc, [N.S.], 1910, 12, 441.

Temperature.

Vap. pressure, mm.

Heat of vaporisation.

Calories.

0°

12.24

220.9

10

23.77

221.2

20

44.00

220.6

30

78.06

220.1

40

-

218.7

50

-

216.0

60

-

213.4

70

-

209.9

80

-

206.4

90

1,194

201.6

100

-

197.1

110

2,356

190.3

120

-

184.2

130

4,320

177.6

140

5,666

171.1

150

7,326

164.7

160

9,366

156.9

170

11,856

148.4

180

14,763

139.2

190

18,178

128.4

200

22,164

116.6

210

26,821

103.2

220

32,097

88.2

230

38,176

70.6

240

45,504

40.3

241

46,210

35.0

242

46,917

28.4

2425

47,206

22.1

243.1

47,850

0

Critical temp.

The specific heat at temperatures from 16° to 40.5° is 0612 (Schiiller); and the critical temperature 2436° at 489 m., 1 gram at this point occupying a volume of 35 c.c. (Ramsay and Young).1

Doroschewsky and Rakowsky2 found the specific heat of ethyl alcohol at 20° to be 0618. For mixtures of alcohol and water, the specific heats over the range 22° to 99° were found to be as follows: -

Percentage of alcohol by weight.

Specific heat.

100.00

0.6597

94.43

0.7089

90.02

0.7390

85.05

0.7732

80.00

0.8030

74.99

0.8309

69.96

0.8603

64.96

0.8859

59.95

0.9079

54.93

0.9296

50.00

0.9489

Percentage of alcohol by weight.

Specific heat.

44.95

0.9702

39.93

0.9924

34.98

1.0116

29.94

1.0277

24.97

1.0411

20.09

1.0440

15.00

1.0422

10.04

1.0300

5.02

1.0169

0.00

1.0067

1 Proc. Roy. Soc, 1885, 38, 329.

2 J. Russ. Phys. Chem. Soc, 1908, 40, 860; Chem. Zentr., 1908, 2, 1568.

L