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Historically, the mole was defined as the amount of substance in 12 grams of the carbon-12 isotope.As a consequence, the mass of one mole of a chemical compound, in grams, is numerically equal (for all practical purposes) to the mass of one molecule or formula unit of the compound, in daltons, and the molar mass of an isotope in grams per mole is approximately equal to the mass number ...
1 mL of water weighs 1 gram so a recipe calling for 300 mL (≈ 1 ⁄ 2 Imperial Pint) of water can simply be substituted with 300 g (≈ 10 oz.) of water. 1 fluid ounce of water weighs approximately 1 ounce so a recipe calling for a UK pint (20 fl oz) of water can be substituted with 20 oz of water.
It follows, therefore, that 1000th of a litre, known as one millilitre (1 mL), of water has a mass of about 1 g; 1000 litres of water has a mass of about 1000 kg (1 tonne or megagram). This relationship holds because the gram was originally defined as the mass of 1 mL of water; however, this definition was abandoned in 1799 because the density ...
The refractive index of liquid water (1.333 at 20 °C (68 °F)) is much higher than that of air (1.0), similar to those of alkanes and ethanol, but lower than those of glycerol (1.473), benzene (1.501), carbon disulfide (1.627), and common types of glass (1.4 to 1.6). The refraction index of ice (1.31) is lower than that of liquid water.
On 7 April 1795, the metric system was formally defined in French law using six units. Three of these are related to volume: the stère (1 m 3) for volume of firewood; the litre (1 dm 3) for volumes of liquid; and the gramme, for mass—defined as the mass of one cubic centimetre of water at the temperature of melting ice. [10]
The gram (originally gramme; [1] SI unit symbol g) is a unit of mass in the International System of Units (SI) equal to one thousandth of a kilogram.. Originally defined as of 1795 as "the absolute weight of a volume of pure water equal to the cube of the hundredth part of a metre [1 cm 3], and at the temperature of melting ice", [2] the defining temperature (≈0 °C) was later changed to 4 ...
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Pure substances that are liquid under normal conditions include water, ethanol and many other organic solvents. Liquid water is of vital importance in chemistry and biology, and it is necessary for all known forms of life. [4] [5] Inorganic liquids include water, magma, inorganic nonaqueous solvents and many acids.