User:Karlhahn/oldSand

Process details

The aparatus shown is divided into two types of cells separated by slate walls. The first type, shown on the right and left of the diagram, uses an electrolyte of of sodium chloride solution, a graphite anode (A), and a mercury cathode (M). The other type of cell, shown in the center of the diagram, uses an electrolyte of sodium hydroxide solution, a mercury anode (M), and an iron cathode (D). Note that the mercury electrode is shared between the two cells. This is achieved by having the walls separating the cells dip below the level of the electrolytes but still allow the mercury to flow beneath them.

The reaction at anode (A) is:

2Cl^– → Cl₂ + 2e^–

The chlorine gas that results vents at the top of the outside cells where it is collected as a byproduct of the process. The reaction at the mercury cathode in the outer cells is

2Na⁺ + 2e^– → 2Na (amalgam)

The sodium metal formed by this reaction dissolves in the mercury to form an amalgam. The mercury conducts the current from the outside cells to the inside cell. In addition, a rocking mechanism (B shown by fulcrum on the left and rotating eccentric on the right) agitates the mercury to transport the dissolved sodium metal from the outside cells to the inside cell.

The anode reaction in the center cell takes place at the interface between the mercury and the sodium hydroxide solution.

2Na + 2e^– → 2Na⁺

Finally at the iron cathode (D) of the center cell the reaction is

2H₂O + 2e^– → 2OH^– + H₂

The net effect is that the concentration of sodium chloride in the outside cells decreases and the concentration of sodium hydroxide in the center cell increases.

Original version

Calcium carbonate is not rigorously insoluble in water. For the following equilibrium reaction

• CaC0₃(solid) ↔ Ca²⁺ + CO₃²⁻, we take a solubility product ${\displaystyle \scriptstyle K_{sp}=[Ca^{2+}][CO_{3}^{2-}]=4.47\times 10^{-9}}$ at 25°C (K_sp=3.8 x 10⁻⁹ is given in ^[5]

Considering a saturated pure CaCO₃ solution, the calculation of the Ca²⁺ concentration must take into account the equilibria between the three different carbonate forms (H₂CO₃, HCO₃⁻ and CO₃²⁻) as well as the equilibrium between H₂CO₃ and the dissolved CO₂ and the equilibrium between the dissolved CO₂ and the gaseous CO₂ above the solution. The reactions involved are the following (see carbonic acid):

• CO₂(gas) ↔ CO₂(dissolved) with ${\displaystyle \scriptstyle {\frac {[CO_{2}]}{p_{CO_{2}}}}={\frac {1}{k'_{c}}}}$ where k'_c=29.76 atm/(mol/L) at 25°C (Henry constant), ${\displaystyle \scriptstyle p_{CO_{2}}}$ being the CO₂ partial pressure.

• CO₂(dissolved) + H₂O ↔ H₂CO₃ with ${\displaystyle \scriptstyle K_{h}={\frac {[H_{2}CO_{3}]}{[CO_{2}]}}=1.70\times 10^{-3}}$ at 25°C

• H₂CO₃ ↔ H⁺ + HCO₃⁻ with ${\displaystyle \scriptstyle K_{a1}={\frac {[H^{+}][HCO_{3}^{-}]}{[H_{2}CO_{3}]}}=2.5\times 10^{-4}}$ at 25°C

• HCO₃⁻ ↔ H⁺ + CO₃²⁻ with ${\displaystyle \scriptstyle K_{a2}={\frac {[H^{+}][CO_{3}^{2-}]}{[HCO_{3}^{-}]}}=5.61\times 10^{-11}}$ at 25°C

The above relations (together with the ${\displaystyle \scriptstyle [H^{+}][OH^{-}]=10^{-14}}$ relation and the neutrality condition ${\displaystyle \scriptstyle 2[Ca^{2+}]+[H^{+}]=[HCO_{3}^{-}]+2[CO_{3}^{2-}]+[OH^{-}]}$, i.e. 7 equations for 7 unknowns) allow the numerical calculation of the pH and of the Ca²⁺ concentration as a function of ${\displaystyle \scriptstyle p_{CO_{2}}}$. The result is given in the table below:

${\displaystyle \scriptstyle p_{CO_{2}}}$ (atm)	pH	[Ca2+] (mol/L)
10−12	12.0	5.19 x 10−3
10−10	11.3	1.12 x 10−3
10−8	10.7	2.55 x 10−4
10−6	9.83	1.20 x 10−4
10−4	8.62	3.16 x 10−4
3.5 x 10−4	8.27	4.70 x 10−4
10−3	7.96	6.62 x 10−4
10−2	7.30	1.42 x 10−3
10−1	6.63	3.05 x 10−3
1	5.96	6.58 x 10−3
10	5.30	1.42 x 10−2

We see that for normal atmospheric conditions (${\displaystyle \scriptstyle p_{CO_{2}}=3.5\times 10^{-4}}$ atm), we get a slightly basic solution (pH = 8.3) with a low Ca²⁺ concentration (4.7 x 10⁻⁴ mol/L i.e. 0.019 g/L of Ca). Increasing the CO₂ pressure makes the solution slightly acid with a better Ca solubility (0.57 g/L of Ca at 10 atm). For decreasing CO₂ pressure values, the solubility goes to a minimum for ${\displaystyle \scriptstyle p_{CO_{2}}=10^{-6}}$ atm and then increases again as the solution gets strongly basic.

Remark: For ${\displaystyle \scriptstyle p_{CO_{2}}}$ > 10⁻⁴ atm, CO₃²⁻, H⁺ and OH⁻ concentrations can be neglected in the neutrality condition. This means physically that we have essentially a calcium bicarbonate solution. In this case, the system can be solved analytically, giving (with a very good precision)

${\displaystyle \scriptstyle [H^{+}]\simeq \left({\frac {K_{a1}^{2}K_{a2}K_{h}^{2}}{2K_{sp}k_{c}^{\prime 2}}}\right)^{1/3}p_{CO_{2}}^{2/3}\;\;\;,\;\;\;[Ca^{2+}]\simeq \left({\frac {K_{a1}K_{sp}K_{h}}{4K_{a2}k_{c}^{\prime }}}\right)^{1/3}p_{CO_{2}}^{1/3}}$

Current state of rewritten version

Calcium carbonate is poorly soluble in water. The equilibrium of its solution is given by the equation (with dissolved calcium carbonate on the right):

CaCO3 ⇋ Ca2+ + CO32–

Ksp = 3.7×10–9 to 8.7×10–9 at 25 °C

where the solubility product for [Ca²⁺][CO₃^2–] is given as anywhere from K_sp = 3.7×10^–9 to K_sp = 8.7×10^–9 at 25 °C, depending upon the data source.^[6][7] What the equation means is that the product of number of moles of dissolved Ca²⁺ with the number of moles of dissolved CO₃^2– cannot exceed the value of K_sp. This seemingly simple solubility equation, however, must be taken along with the more complicated equilibrium of carbon dioxide with water. Some of the CO₃^2– combines with H⁺ in the solution according to:

HCO3– ⇋ H+ + CO32–

Ka2 = 5.61×10–11 at 25 °C

HCO₃^– is known as the bicarbonate ion. Calcium bicarbonate is many times more soluble in water than calcium carbonate -- indeed it exists only in solution.

Some of the HCO₃^– combines with H⁺ in solution according to:

H2CO3 ⇋ H+ + HCO3–

Ka1 = 2.5×10–4 at 25 °C

Some of the H₂CO₃ breaks up into water and dissolved carbon dioxide according to:

H2O + CO2(dissolved) ⇋ H2CO3

Kh = 1.70×10–3 at 25 °C

And dissolved carbon dioxide is in equilibrium with atmospheric carbon dioxide according to:

${\displaystyle {\frac {P_{\mathrm {CO} _{2}}}{[\mathrm {CO} _{2}]}}\ =\ k'_{c}}$

where k'c = 29.76 atm/(mol/L) at 25°C (Henry constant), ${\displaystyle \scriptstyle P_{\mathrm {CO} _{2}}}$ being the CO2 partial pressure.

Calcium Ion Solubility as a function of CO2 partial pressure
${\displaystyle \scriptstyle P_{\mathrm {CO} _{2}}}$ (atm)	pH	[Ca2+] (mol/L)
10−12	12.0	5.19 × 10−3
10−10	11.3	1.12 × 10−3
10−8	10.7	2.55 × 10−4
10−6	9.83	1.20 × 10−4
10−4	8.62	3.16 × 10−4
3.5 × 10−4	8.27	4.70 × 10−4
10−3	7.96	6.62 × 10−4
10−2	7.30	1.42 × 10−3
10−1	6.63	3.05 × 10−3
1	5.96	6.58 × 10−3
10	5.30	1.42 × 10−2

For ambient air, ${\displaystyle \scriptstyle P_{\mathrm {CO} _{2}}}$ is around 3.5×10^–4 atmospheres (or equivalently 35 Pa). The last equation above fixes the concentration of dissolved CO₂ as a function of ${\displaystyle \scriptstyle P_{\mathrm {CO} _{2}}}$, independent of the concentration of dissolved CaCO₃. At atmospheric partial pressure of CO₂, dissolved CO₂ concentration is 1.2×10^–5 moles/liter. The equation before that fixes the concentration of H₂CO₃ as a function of [CO₂]. For [CO₂]=1.2×10^–5, it results in [H₂CO₃]=2.0×10^–8 moles per liter. When [H₂CO₃] is known, the remaining three equations together with

H2O ⇋ H+ + OH–

K = 10–14 at 25 °C

(which is true for all aqueous solutions), and the fact that the solution must be electrically neutral,

2[Ca²⁺] + [H⁺] = [HCO₃^–] + 2[CO₃^2–] + [OH^–]

make it possible to solve simultaneously for the remaining five unknown concentrations. The table on the right shows the solution for [Ca²⁺] and [H⁺] (in the form of pH) as a function of ambient partial pressure of CO₂. At atmopheric levels of ambient CO₂ the table indicates the solution will be slightly alkaline. The trends the table shows are

1) As ambient CO₂ partial pressure is reduced below atmospheric levels, the solution becomes more and more alkaline. At extremly low ${\displaystyle \scriptstyle P_{\mathrm {CO} _{2}}}$, dissolved CO₂, bicarbonate ion, and carbonate ion largely evaporate from the solution, leaving a highly alkaline solution of calcium hydroxide, which is more soluble than CaCO₃.

2) As ambient CO₂ partial pressure increases to levels above atmospheric, pH drops, and much of the carbonate ion is converted to bicarbonate ion, which results in higher solubility of Ca²⁺.

The effect of the latter is especially evident in day to day life of people who have hard water. Water in aquifers underground can be exposed to levels of CO₂ much higher than atmospheric. As such water perculates through calcium carbonate rock, the CaCO₃ dissolves according to the second trend. When that same water then water emerges from the tap, in time it comes into equilibrium with CO₂ levels in the air by outgassing its excess CO₂. The calcium carbonate becomes less soluble as a result and the excess precipitates as lime scale. This same process is responsible for the formation of stalactites and stalagmites in limestone caves.

Equilibrium of vapor over aqueous solution

Summary of Calendar Calculations

The audience for this section is computer programmers who wish to write software that accurately computes dates in the Hebrew calendar. The following details are sufficient to generate such software.

1) The Hebrew calendar is computed by lunations. One lunation is reckoned at 29 days, 12 hours, 44 minutes, 3⅓ seconds, or equivalently 765433 halakim = 29 days, 13753 halakim.

2) A common year must be either 353, 354, or 355 days; a leap year must be 383, 384, or 385 days. A 353 or 383 day year is called kesidrah. A 354 or 384 day year is shelemah. A 355 or 385 day year is haserah.

3) Leap years follow a 19 year schedule in which years 3, 6, 8, 11, 14, 17, and 19 are leap years. The Jewish year 5752 (which starts in Gregorian year 1991) is the first year of a cycle.

4) 19 years is the same as 235 lunations.

5) The months are Tishri, Heshvan, Kislev, Tebeth, Shebhat, Adar, Nisan, Iyyar, Sivan, Tammuz, Av, and Elul. In addition, a second Adar (also called Veadar, Adar II, or Adar Sheni) is added in leap years. When added, it follows Adar.

6) Each month has either 29 or 30 days. A 30 day month is male, a 29 day month is haser.

Nisan, Sivan, Av, Tishri, and Shebhat are always male.

Iyyar, Tammuz, Elul, Tebeth, and Adar II are always haser.

Adar is male in leap years, haser in common years.

Heshvan and Kislev vary, but when they differ, Heshvan is haser and Kislev is male.

7) Tishri 1st (Rosh Hashana) is the day of a molad (new moon) unless certain conditions (dahiyyah sing; dahiyyot pl) exist.

a) This dahiyyah exists whenever Tishri 10 (Yom Kippur) would fall on a Friday or a Sunday, or if Tishri 21 (7th day of Sukkot) would fall on a Saturday. This is equivalent to the molad being on Sunday, Wednesday, or Friday. Whenever this happens, Tishri 1 is delayed by 1 day.

b) This dahiyyah exists whenever the molad occurs on or after noon. When this dahiyyah exists, Tishri 1 is delayed by 1 day. If this causes dahiyyah A to exist, Tishri 1 is delayed an additional day.

c) If the year is to be a common year and the molad falls on a Tuesday on or after 3:11:20 am (3 hours 204 halakim) Jerusalem time, Tishri 1 is delayed by 2 days. This is because if it weren't delayed, the resulting year would be 356 days long.

d) If the new year follows a leap year and the molad is on a Monday on or after 9:32:43 and one third seconds (9 hours 589 halakim), Tishri 1 is delayed 1 day. This is because if it weren't, the preceding year would have only 382 days.

8) Delays are implemented by adding a day to Kislev of the preceding year, making it male. If Kislev is already male, the day is added to Heshvan of the preceding year, making it male also. If a delay of 2 days is called for, both Heshvan and Kislev of the preceding year become male.

9) The molad of 08-Sep-1991, which is Rosh Hashana of Hebrew yer, 5752, is Julian day, 2448509 plus 3294 halakim.

Current version of translation

Physical and Thermodynamic Tables

In the following tables, values are temperature dependent and to a lesser degree pressure dependent, and are arranged by state of aggregation (s=solid, lq=liquid, g=gas), which are clearly a function of temperature and pressure. All of the data were computed from data given in "Formulation of the Thermodynamic Properties of Ordinary Water Substance for Scientific and General Use" (1984). This applies to:

• T - temperature in degrees celsius
• V - specific volume in decimeter³ per kilogram
• H - specific enthalpy in kJ per kilogram
• U - internal energy in kJ per kilogram
• S - specific entropy in kJ per kilogram-Kelvin
• c_p - specific (constant pressure) heat capacity in kJ per kilogram-Kelvin
• γ - Thermal expansion coefficient as 10^–3 per Kelvin
• λ - Heat conductivity in milliwatt per meter-Kelvin
• η - Viscosity in μPa-seconds
• σ - Surface Tension millinewtons per meter

Triple Point

In the following table, material data is given with a pressure of 0.0006117 MPa (equivalent to 0.006117 bar). Up to a temperature of 0.01 °C, the triple point of water, water normally exists as ice, except for supercooled water, for which one data point is tabulated here. At the triple point ice can exist together with both liquid water and vapor. At higher temperatures the data is for water vapor only.

Saturated Vapor Pressure

The following table is based on different, complementary sources and approximation formulas, whose values are of various quality and accuracy. The values in the temperature range of –100 °C to 100 °C were inferred from D. Sunday (1982) and are quite uniform and exact. The values in the temperature range of the boiling point of the water up to the critical point (100 °C to 374 °C), are drawn from different sources and are substantially less accurate, hence they should be understood and used also only as approximate values.^{[13][14][15][16]}

To use the values corrctly, consider the following points:

• The values apply only to smooth interfaces and in the absence other gases or gas mixtures such as air. Hence they apply only to pure phases and need a correction factor for systems in which air is present.
• The values were not computed according formulas widely used in the US, but using somewhat more exact formulas (see below), which can also also be used to compute further values in the appropriate temperature ranges.
• The saturated steam pressure over water in the temperature range of –100 °C to –50 °C is only extrapolated.
• The values have various units (Pa, hPa or bar), which must be considered when reading them.

Drucktabellen

Die in der folgenden Tabelle dargestellten Größen sind temperatur- und teilweise auch druckabhängig, richten sich aber in jedem Fall nach dem Aggregatzustand des Wassers (hier s = fest; l = flüssig; g = gasförmig). Dieser wird durch Druck und Temperatur eindeutig bestimmt. Alle Daten wurden Grigull et. al. (1990) entnommen, welche sie nach der Vorgabe durch die "Formulation of the Thermodynamic Properties of Ordinary Water Substance for Scientific and General Use" (1984) der IAPWS mit einer verringerten Iterationsschranke berechneten. Es handelt sich um:

• ${\displaystyle \vartheta }$ - die Celsius-Temperatur in Grad Celsius
• v – das spezifische Volumen in Kubikdezimeter je Kilogramm
• h – die spezifische Enthalpie in Kilojoule je Kilogramm
• u – die spezifische Innere Energie in Kilojoule je Kilogramm
• s – die spezifische Entropie in Kilojoule je Kilogramm mal Kelvin
• c_p - die spezifische Wärmekapazität bei konstantem Druck in Kilojoule je Kilogramm mal Kelvin
• γ – Volumenausdehnungskoeffzient in 10^-3 durch Kelvin
• λ – Wärmeleitfähigkeit in Milliwatt je Meter mal Kelvin
• η – Viskosität in Mikropascal mal Sekunde
• σ – Oberflächenspannung in Millinewton je Meter

Standardbedingungen

In der folgenden Tabelle handelt es sich um die Stoffdaten bei Standarddruck (SATP), also 0,1 Megapascal (entspricht einem bar). Bis zu einer Temperatur von 99,63 °C, dem Siedepunkt des Wasser bei diesem Druck, liegt das Wasser als Flüssigkeit vor, darüber als Wasserdampf.

${\displaystyle \vartheta }$ °C		v dm³/kg	h kJ/kg	u kJ/kg	s kJ/(kg·K)	cp kJ/(kg·K)	γ 10-3/K	λ mW / (m·K)	η μPa·s	σ1 mN/m
0		1,0002	0,06	-0,04	-0,0001	4,228	-0,080	561,0	1792	75,65
5		1,0000	21,1	21,0	0,076	4,200	0,011	570,6	1518	74,95
10		1,0003	42,1	42,0	0,151	4,188	0,087	580,0	1306	74,22
15		1,0009	63,0	62,9	0,224	4,184	0,152	589,4	1137	73,49
20		1,0018	83,9	83,8	0,296	4,183	0,209	598,4	1001	72,74
25		1,0029	104,8	104,7	0,367	4,183	0,259	607,2	890,4	71,98
30		1,0044	125,8	125,7	0,437	4,183	0,305	615,5	797,7	71,20
35		1,0060	146,7	146,6	0,505	4,183	0,347	623,3	719,6	70,41
40		1,0079	167,6	167,5	0,572	4,182	0,386	630,6	653,3	69,60
45		1,0099	188,5	188,4	0,638	4,182	0,423	637,3	596,3	68,78
50		1,0121	209,4	209,3	0,704	4,181	0,457	643,6	547,1	67,95
60		1,0171	251,2	251,1	0,831	4,183	0,522	654,4	466,6	66,24
70		1,0227	293,1	293,0	0,955	4,187	0,583	663,1	404,1	64,49
80		1,0290	335,0	334,9	1,075	4,194	0,640	670,0	354,5	62,68
90		1,0359	377,0	376,9	1,193	4,204	0,696	675,3	314,6	60,82
99,63	l	1,0431	417,5	417,4	1,303	4,217	0,748	679,0	283,0	58,99
	g	1694,3	2675	2505	7,359	2,043	2,885	25,05	12,26	–
100		1696,1	2675	2506	7,361	2,042	2,881	25,08	12,27	58,92
200		2172,3	2874	2657	7,833	1,975	2,100	33,28	16,18	37,68
300		2638,8	3073	2810	8,215	2,013	1,761	43,42	20,29	14,37
500		3565,5	3488	3131	8,834	2,135	1,297	66,970	28,57	–
750		4721,0	4043	3571	9,455	2,308	0,978	100,30	38,48	–
1000		5875,5	4642	4054	9,978	2,478	0,786	136,3	47,66	–
1 Die Werte der Oberflächenspannung gelten nicht für den Normaldruck, sondern für den zur jeweiligen Temperatur gehörigen Sättigungsdampfdruck.

Tripelpunkt

In der folgenden Tabelle handelt es sich um die Stoffdaten bei einem Druck von 0,0006117 Megapascal (entspricht 0,006117 bar). Bis zu einer Temperatur von 0,01 °C, dem Tripelpunkt des Wassers, liegt das Wasser normalerweise als Eis vor, wurde jedoch hier für unterkühltes Wasser tabelliert. Am Tripelpunkt selbst kann es sowohl als Eis als auch Flüssigkeit oder Wasserdampf vorliegen, bei höheren Temperaturen handelt es sich jedoch wiederum um Wasserdampf.

${\displaystyle \vartheta }$ °C		v dm³/kg	h kJ/kg	u kJ/kg	s kJ/(kg·K)	cp kJ/(kg·K)	γ 10-3/K	λ mW / (m·K)	η μPa·s	σ1 mN/m
0		1,0002	-0,04	-0,04	-0,0002	4,339	-0,081	561,0	1792	–
0,1	s	1,0908	-333,4	-333,4	-1,221	1,93	0,1	2,2	–	–
	l	1,0002	0,0	0	0	4,229	-0,080	561,0	1791	–
	g	205986	2500	2374	9,154	1,868	3,672	17,07	9,22	–
5		209913	2509	2381	9,188	1,867	3,605	17,33	9,34	–
10		213695	2519	2388	9,222	1,867	3,540	17,60	9,46	–
15		217477	2528	2395	9,254	1,868	3,478	17,88	9,59	–
20		221258	2537	2402	9,286	1,868	3,417	18,17	9,73	–
25		225039	2547	2409	9,318	1,869	3,359	18,47	9,87	–
30		228819	2556	2416	9,349	1,869	3,304	18,78	10,02	–
35		232598	2565	2423	9,380	1,870	3,249	19,10	10,17	–
40		236377	2575	2430	9,410	1,871	3,197	19,43	10,32	–
45		240155	2584	2437	9,439	1,872	3,147	19,77	10,47	–
50		243933	2593	2444	9,469	1,874	3,098	20,11	10,63	–
60		251489	2612	2459	9,526	1,876	3,004	20,82	10,96	–
70		259043	2631	2473	9,581	1,880	2,916	21,56	11,29	–
80		266597	2650	2487	9,635	1,883	2,833	22,31	11,64	–
90		274150	2669	2501	9,688	1,887	2,755	23,10	11,99	–
100		281703	2688	2515	9,739	1,891	2,681	23,90	12,53	–
200		357216	2879	2661	10,194	1,940	2,114	32,89	16,21	–
300		432721	3076	2811	10,571	2,000	1,745	43,26	20,30	–
500		583725	3489	3132	11,188	2,131	1,293	66,90	28,57	–
750		772477	4043	3571	11,808	2,307	0,977	100,20	38,47	–
1000		961227	4642	4054	12,331	2,478	0,785	136,30	47,66	–
1 Die Werte der Oberflächenspannung sind hier identisch zur ersten Tabelle, wobei in gleicherweise der Sättigungsdampfdruck angewendet werden muss.

Formeln

Berechnet wurden die Tabellenwerte von -100 °C bis 100 °C durch folgende Formeln:

Über Wasser:

${\displaystyle E_{w}(T)=\exp \left(-6094{,}4642\cdot T^{-1}+21{,}1249952-2{,}724552\cdot 10^{-2}\cdot T+1{,}6853396\cdot 10^{-5}\cdot T^{2}+2{,}4575506\cdot \ln T\right)}$

Temperaturintervall:

${\displaystyle 173{,}15\ \mathrm {K} \leq T\leq 373{,}15\ \mathrm {K} }$, entspricht ${\displaystyle -100\,^{\circ }\mathrm {C} \leq t\leq 100\,^{\circ }\mathrm {C} }$

Über Eis:

${\displaystyle E_{i}(T)=\exp \left(-5504{,}4088\cdot T^{-1}-3{,}5704628-1{,}7337458\cdot 10^{-2}\cdot T+6{,}5204209\cdot 10^{-6}\cdot T^{2}+6{,}1295027\cdot \ln T\right)}$

Temperaturintervall:

${\displaystyle 173{,}15\ \mathrm {K} \leq T\leq 273{,}15\ \mathrm {K} }$, entspricht ${\displaystyle -100\,^{\circ }\mathrm {C} \leq t\leq 0\,^{\circ }\mathrm {C} }$

Werden die Temperaturen in Kelvin eingesetzt, so ergibt sich der jeweilige Sättigungsdampfdruck E(T) in Pa.

Tripelpunkt

Ein wichtiger Grundwert, der nicht in die Tabelle eingetragen wurde, ist der Sättigungsdampfdruck beim Tripelpunkt des Wassers. Der international akzeptierte Bestwert nach Messungen von Guildner, Johnson und Jones (1976) beträgt:

${\displaystyle E_{w}(t_{tr}=0{,}01\,^{\circ }\mathrm {C} )=611{,}657\ \mathrm {Pa} \ \pm 0{,}010\ \mathrm {Pa} \ \mathrm {bei} \ (1-\alpha )=99\mathrm {\%} }$

Tabelle

More information , ...

Beispielwerte des Sättigungsdampfdrucks von Wasser

Temperatur t in °C	${\displaystyle E_{i}}$(t) über Eis p in Pa	${\displaystyle E_{w}}$(t) über Wasser p in Pa	Temperatur t in °C	E(t) über Wasser p in hPa	Temperatur t in °C	E(t) p in bar	Temperatur t in °C	E(t) p in bar	Temperatur t in °C	E(t) p in bar
-100	0,0013957	0,0036309	0	6,11213	100	1,01	200	15,55	300	85,88
-99	0,0017094	0,0044121	1	6,57069	101	1,05	201	15,88	301	87,09
-98	0,0020889	0,0053487	2	7,05949	102	1,09	202	16,21	302	88,32
-97	0,002547	0,0064692	3	7,58023	103	1,13	203	16,55	303	89,57
-96	0,0030987	0,0078067	4	8,13467	104	1,17	204	16,89	304	90,82
-95	0,0037617	0,0093996	5	8,72469	105	1,21	205	17,24	305	92,09
-94	0,0045569	0,011293	6	9,35222	106	1,25	206	17,6	306	93,38
-93	0,0055087	0,013538	7	10,0193	107	1,3	207	17,96	307	94,67
-92	0,0066455	0,016195	8	10,728	108	1,34	208	18,32	308	95,98
-91	0,0080008	0,019333	9	11,4806	109	1,39	209	18,7	309	97,31
-90	0,0096132	0,023031	10	12,2794	110	1,43	210	19,07	310	98,65
-89	0,011528	0,027381	11	13,1267	111	1,48	211	19,46	311	100
-88	0,013797	0,032489	12	14,0251	112	1,53	212	19,85	312	101,37
-87	0,016482	0,038474	13	14,9772	113	1,58	213	20,25	313	102,75
-86	0,019653	0,045473	14	15,9856	114	1,64	214	20,65	314	104,15
-85	0,02339	0,053645	15	17,0532	115	1,69	215	21,06	315	105,56
-84	0,027788	0,063166	16	18,1829	116	1,75	216	21,47	316	106,98
-83	0,032954	0,074241	17	19,3778	117	1,81	217	21,89	317	108,43
-82	0,039011	0,087101	18	20,6409	118	1,86	218	22,32	318	109,88
-81	0,046102	0,10201	19	21,9757	119	1,93	219	22,75	319	111,35
-80	0,054388	0,11925	20	23,3854	120	1,99	220	23,19	320	112,84
-79	0,064057	0,13918	21	24,8737	121	2,05	221	23,64	321	114,34
-78	0,07532	0,16215	22	26,4442	122	2,12	222	24,09	322	115,86
-77	0,088419	0,1886	23	28,1006	123	2,18	223	24,55	323	117,39
-76	0,10363	0,21901	24	29,847	124	2,25	224	25,02	324	118,94
-75	0,12127	0,25391	25	31,6874	125	2,32	225	25,49	325	120,51
-74	0,14168	0,2939	26	33,626	126	2,4	226	25,98	326	122,09
-73	0,16528	0,33966	27	35,6671	127	2,47	227	26,46	327	123,68
-72	0,19252	0,39193	28	37,8154	128	2,55	228	26,96	328	125,3
-71	0,22391	0,45156	29	40,0754	129	2,62	229	27,46	329	126,93
-70	0,26004	0,51948	30	42,452	130	2,7	230	27,97	330	128,58
-69	0,30156	0,59672	31	44,9502	131	2,78	231	28,48	331	130,24
-68	0,34921	0,68446	32	47,5752	132	2,87	232	29,01	332	131,92
-67	0,40383	0,78397	33	50,3322	133	2,95	233	29,54	333	133,62
-66	0,46633	0,89668	34	53,2267	134	3,04	234	30,08	334	135,33
-65	0,53778	1,0242	35	56,2645	135	3,13	235	30,62	335	137,07
-64	0,61933	1,1682	36	59,4513	136	3,22	236	31,18	336	138,82
-63	0,71231	1,3306	37	62,7933	137	3,32	237	31,74	337	140,59
-62	0,81817	1,5136	38	66,2956	138	3,42	238	32,31	338	142,37
-61	0,93854	1,7195	39	69,9675	139	3,51	239	32,88	339	144,18
-60	1,0753	1,9509	40	73,8127	140	3,62	240	33,47	340	146
-59	1,2303	2,2106	41	77,8319	141	3,72	241	34,06	341	147,84
-58	1,406	2,5018	42	82,0536	142	3,82	242	34,66	342	149,71
-57	1,6049	2,8277	43	86,4633	143	3,93	243	35,27	343	151,58
-56	1,8296	3,1922	44	91,0757	144	4,04	244	35,88	344	153,48
-55	2,0833	3,5993	45	95,8984	145	4,16	245	36,51	345	155,4
-54	2,3694	4,0535	46	100,939	146	4,27	246	37,14	346	157,34
-53	2,6917	4,5597	47	106,206	147	4,39	247	37,78	347	159,3
-52	3,0542	5,1231	48	111,708	148	4,51	248	38,43	348	161,28
-51	3,4618	5,7496	49	117,452	149	4,64	249	39,09	349	163,27
-50	3,9193	6,4454	50	123,4478	150	4,76	250	39,76	350	165,29
-49	4,4324	7,2174	51	129,7042	151	4,89	251	40,44	351	167,33
-48	5,0073	8,0729	52	136,2304	152	5,02	252	41,12	352	169,39
-47	5,6506	9,0201	53	143,0357	153	5,16	253	41,81	353	171,47
-46	6,3699	10,068	54	150,1298	154	5,29	254	42,52	354	173,58
-45	7,1732	11,225	55	157,5226	155	5,43	255	43,23	355	175,7
-44	8,0695	12,503	56	165,2243	156	5,58	256	43,95	356	177,85
-43	9,0685	13,911	57	173,2451	157	5,72	257	44,68	357	180,02
-42	10,181	15,463	58	181,5959	158	5,87	258	45,42	358	182,21
-41	11,419	17,17	59	190,2874	159	6,03	259	46,16	359	184,43
-40	12,794	19,048	60	199,3309	160	6,18	260	46,92	360	186,66
-39	14,321	21,11	61	208,7378	161	6,34	261	47,69	361	188,93
-38	16,016	23,372	62	218,5198	162	6,5	262	48,46	362	191,21
-37	17,893	25,853	63	228,6888	163	6,67	263	49,25	363	193,52
-36	19,973	28,57	64	239,2572	164	6,84	264	50,05	364	195,86
-35	22,273	31,544	65	250,2373	165	7,01	265	50,85	365	198,22
-34	24,816	34,795	66	261,6421	166	7,18	266	51,67	366	200,61
-33	27,624	38,347	67	273,4845	167	7,36	267	52,49	367	203,02
-32	30,723	42,225	68	285,7781	168	7,55	268	53,33	368	205,47
-31	34,14	46,453	69	298,5363	169	7,73	269	54,17	369	207,93
-30	37,903	51,06	70	311,7731	170	7,92	270	55,03	370	210,43
-29	42,046	56,077	71	325,5029	171	8,11	271	55,89	371	212,96
-28	46,601	61,534	72	339,7401	172	8,31	272	56,77	372	215,53
-27	51,607	67,466	73	354,4995	173	8,51	273	57,66	373	218,13
-26	57,104	73,909	74	369,7963	174	8,72	274	58,56	374	220,64
-25	63,134	80,902	75	385,6459	175	8,92	275	59,46	374,15	221,2
-24	69,745	88,485	76	402,0641	176	9,14	276	60,38
-23	76,987	96,701	77	419,0669	177	9,35	277	61,31
-22	84,914	105,6	78	436,6708	178	9,57	278	62,25
-21	93,584	115,22	79	454,8923	179	9,8	279	63,2
-20	103,06	125,63	80	473,7485	180	10,03	280	64,17
-19	113,41	136,88	81	493,2567	181	10,26	281	65,14
-18	124,7	149,01	82	513,4345	182	10,5	282	66,12
-17	137,02	162,11	83	534,3	183	10,74	283	67,12
-16	150,44	176,23	84	555,8714	184	10,98	284	68,13
-15	165,06	191,44	85	578,1673	185	11,23	285	69,15
-14	180,97	207,81	86	601,2068	186	11,49	286	70,18
-13	198,27	225,43	87	625,009	187	11,75	287	71,22
-12	217,07	244,37	88	649,5936	188	12,01	288	72,27
-11	237,49	264,72	89	674,9806	189	12,28	289	73,34
-10	259,66	286,57	90	701,1904	190	12,55	290	74,42
-9	283,69	310,02	91	728,2434	191	12,83	291	75,51
-8	309,75	335,16	92	756,1608	192	13,11	292	76,61
-7	337,97	362,1	93	784,9639	193	13,4	293	77,72
-6	368,52	390,95	94	814,6743	194	13,69	294	78,85
-5	401,58	421,84	95	845,3141	195	13,99	295	79,99
-4	437,31	454,88	96	876,9057	196	14,29	296	81,14
-3	475,92	490,19	97	909,4718	197	14,6	297	82,31
-2	517,62	527,93	98	943,0355	198	14,91	298	83,48
-1	562,62	568,22	99	977,6203	199	15,22	299	84,67
0	611,153	611,213	100	1013,25	200	15,55	300	85,88

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