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The values below 0 °C refer to supercooled water. Viscosity [11] 1.7921 mPa·s at 0 °C 0.5494 mPa·s at 50 °C 1.5188 mPa·s at 5 °C 0.5064 mPa·s at 55 °C 1.3077 mPa·s at 10 °C 0.4688 mPa·s at 60 °C 1.1404 mPa·s at 15 °C 0.4355 mPa·s at 65 °C 1.0050 mPa·s at 20 °C 0.4061 mPa·s at 70 °C 0.8937 mPa·s at 25 °C
Water has a very high specific heat capacity of 4184 J/(kg·K) at 20 °C (4182 J/(kg·K) at 25 °C) —the second-highest among all the heteroatomic species (after ammonia), as well as a high heat of vaporization (40.65 kJ/mol or 2268 kJ/kg at the normal boiling point), both of which are a result of the extensive hydrogen bonding between its ...
The interest stems from that accurate measurements of the unit cell volume, atomic weight and mass density of a pure crystalline solid provide a direct determination of the Avogadro constant. [ 3 ] The CODATA recommended value for the molar volume of silicon is 1.205 883 199 (60) × 10 −5 m 3 ⋅mol −1 , with a relative standard uncertainty ...
(at 25 °C) (5.727 rel. to water at 4 °C) CRC ... — "Values ranging from 21.3 to 21.5 gm/cm 3 at 20 °C have been reported for the density of annealed platinum; ...
In spite of the fact that the decreed definition of the gram specified water at 0 °C (32 °F)—a highly reproducible temperature—the scientists chose to redefine the standard and to perform their measurements at the temperature of highest water density, which was measured at the time as 4 °C (39 °F). [126]
Table of specific heat capacities at 25 °C (298 K) unless otherwise noted. [citation needed] Notable minima and maxima are shown in maroon. Substance Phase Isobaric mass heat capacity c P J⋅g −1 ⋅K −1 Molar heat capacity, C P,m and C V,m J⋅mol −1 ⋅K −1 Isobaric volumetric heat capacity C P,v J⋅cm −3 ⋅K −1 Isochoric ...
For example, SG (20 °C/4 °C) would be understood to mean that the density of the sample was determined at 20 °C and of the water at 4 °C. Taking into account different sample and reference temperatures, while SG H 2 O = 1.000 000 (20 °C/20 °C), it is also the case that SG H 2 O = 0.998 2008 ⁄ 0.999 9720 = 0.998 2288 (20 °C/4 °C).
Thus pKw D 2 O = p[OD −] + p[D +] = 7.44 + 7.44 = 14.87 (25.0 °C), and the p[D +] of neutral heavy water at 25.0 °C is 7.44. The pD of heavy water is generally measured using pH electrodes giving a pH (apparent) value, or pHa, and at various temperatures a true acidic pD can be estimated from the directly pH meter measured pHa, such that ...