Water exhibits unusual volumetric behavior near its freezing point. The densities given below were measured at 1 atm.
Temperature (°C)
State
Density (g cm⁻³)
0
Liquid
0.9998
–5
Solid
0.9167
Molar mass of H₂O = 18.02 g mol⁻¹.
(a) Calculate the molar volume of liquid water at 0 °C.
(b) Calculate the molar volume of ice at –5 °C.
(c) Contrast the trend you observe with the trend expected for most other substances when they freeze. Explain the molecular origin of the anomaly in terms of the dominant intermolecular forces and the resulting three-dimensional arrangement of H₂O molecules in ice.
(d) Discuss one significant environmental consequence of the difference in molar volume between ice and liquid water.