Paul Flowers; Klaus Theopold; Richard Langley; William R. Robinson, PhD

Water Density (g/mL) at Different Temperatures (°C)

Temperature	Density (g/mL)
0	0.9998395
4	0.9999720 (density maximum)
10	0.9997026
15	0.9991026
20	0.9982071
22	0.9977735
25	0.9970479
30	0.9956502
40	0.9922
60	0.9832
80	0.9718
100	0.9584

Table E1

Water Vapor Pressure at Different Temperatures (°C)

Temperature	Vapor Pressure (torr)	Vapor Pressure (Pa)
0	4.6	613.2812
4	6.1	813.2642
10	9.2	1226.562
15	12.8	1706.522
20	17.5	2333.135
22	19.8	2639.776
25	23.8	3173.064
30	31.8	4239.64
35	42.2	5626.188
40	55.3	7372.707
45	71.9	9585.852
50	92.5	12332.29
55	118.0	15732
60	149.4	19918.31
65	187.5	24997.88
70	233.7	31157.35
75	289.1	38543.39
80	355.1	47342.64
85	433.6	57808.42
90	525.8	70100.71
95	633.9	84512.82
100	760.0	101324.7

Table E2

Water K_w and pK_w at Different Temperatures (°C)

Temperature	K_w 10^–14	pK_w¹
0	0.112	14.95
5	0.182	14.74
10	0.288	14.54
15	0.465	14.33
20	0.671	14.17
25	0.991	14.00
30	1.432	13.84
35	2.042	13.69
40	2.851	13.55
45	3.917	13.41
50	5.297	13.28
55	7.080	13.15
60	9.311	13.03
75	19.95	12.70
100	56.23	12.25

Table E3

Specific Heat Capacity for Water

C°(H₂O(l)) = 4.184 J∙g^-1∙°C^-1
C°(H₂O(s)) = 2.093 J∙g⁻¹∙°C⁻¹
C°(H₂O(g)) = 1.864 J∙g⁻¹∙°C⁻¹

Table E4

Standard Water Melting and Boiling Temperatures and Enthalpies of the Transitions

	Temperature (K)	ΔH (kJ/mol)
melting	273.15	6.088
boiling	373.15	40.656 (44.016 at 298 K)

Table E5

Water Cryoscopic (Freezing Point Depression) and Ebullioscopic (Boiling Point Elevation) Constants

K_f = 1.86°C∙kg∙mol⁻¹ (cryoscopic constant)
K_b = 0.51°C∙kg∙mol⁻¹ (ebullioscopic constant)

Table E6

A line graph is titled “Water Full-Range Spectral Absorption Curve.” The x-axis is titled “Wavelength” and the y-axis is titled “Absorption ( 1 per meter ).” Evenly spaced tick marks on the x-axis denote 10 nanometers, 100 nanometers, 1 micrometer, 10 micrometers, 100 micrometers, 1 millimeter, and 10 millimeters. Evenly spaced tick marks on the y-axis denote 10 superscript negative two, 10 superscript negative one, 10 superscript zero, 10 superscript one, 10 superscript two, 10 superscript three, 10 superscript four, 10 superscript five, 10 superscript six, 10 superscript seven, and 10 superscript eight. Above the graph, horizontal lines indicate the range of wavelengths for U V, V I S, near I R , mid I R , far I R , and E H F. The graph contains one line that begins at 10 nanometers and a little more than 10 superscript six. Moving from left to right, this line ascends gradually until it reaches a point near 100 nanometers and 10 superscript eight. From this point, the line steeply descends to a point a little more than halfway between 100 nanometers and 1 micrometer, and slightly more than 10 superscript two. This point indicates the end of the range labeled “U V” and the beginning of the range labeled “V I S.” The range labeled “V I S” is shaded with a color spectrum including the full range of Roy G Biv colors. Here, the line briefly descends in the same path as before, and then steeply ascends to a point near 1 micrometer and 10 superscript zero. This point indicates the end of the range labeled “V I S” and the beginning of the range labeled “near I R.” The line continues its steep ascent, with short, abrupt descents in between, until it reaches a point a little more than halfway between 1 micrometer and 10 micrometers, and a little more than 10 superscript six. This point indicates the end of the range labeled “near I R” and the beginning of the range labeled “mid I R.” Here, the line moves steeply and sporadically up and down until it reaches a point a little more than halfway between 10 micrometers and 100 micrometers, and slightly more than 10 superscript five. This point indicates the end of the range labeled “Mid I R” and the beginning of the range labeled “Far I R.” The line descends very gradually to a point slightly more than 1 millimeter and slightly more than 10 superscript four. This point indicates the end of the range labeled “Far I R” and the beginning of the range labeled “E H F.” The line continues its gradual descent to 10 millimeters and slightly more than 10 superscript three. This point indicates the end of the range labeled “E H F.”

Figure E1 The plot shows the extent of light absorption versus wavelength for water. Absorption is reported in reciprocal meters and corresponds to the inverse of the distance light may travel through water before its intensity is diminished by 1/e (~37%).

Footnotes

1pK_w = –log₁₀(K_w)

E | Water Properties

Footnotes