What is the density of pure water?
The density of water is dependent on its temperature, but the relation is not linear and is not even monotonic (see table below though it may be difficult to read due to poor Y formatting capability). When cooled from room temperature liquid water becomes increasingly dense, just like other substances. But at approximately 4 °C, water reaches its maximum density. As it is cooled further under ambient conditions, it expands to become less dense. This unusual negative thermal expansion is attributed to strong, orientation-dependent, intermolecular interactions and is also observed in molten silica. Temp (°C) Density (kg/m3) +100 958.4 +80 971.8 +60 983.2 +40 992.2 +30 995.6502 +25 997.0479 +22 997.7735 +20 998.2071 +15 999.1026 +10 999.7026 +4 999.9720 0 999.8395 −10 998.117 −20 993.547 −30 983.854 The values below 0 °C refer to supercooled water.
