Liquid water at 0 °C has a density of 0.997 g mL⁻¹
CHEMISTRY · Single correct · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
Liquid water at 0 °C has a density of 0.997 g mL⁻¹, while ice at 0 °C has a density of 0.917 g mL⁻¹. For 1 mol of H₂O, what is the approximate percent change in volume when the water freezes, and what is the primary molecular reason for this change?
(a) A decrease of about 9%, primarily because the molecules are packed more efficiently in the solid state
(b) An increase of about 0.9%, primarily because hydrogen bonding weakens in the solid
(c) An increase of about 9%, primarily because the hydrogen-bonded lattice in ice is an open structure that occupies more space
(d) An increase of about 9%, primarily because the kinetic energy of the molecules drops sharply upon freezing