Forces Between Molecules

Molecules attract one another, weakly but constantly, and those attractions decide whether a substance is a gas, a liquid or a solid at room temperature. Play boiling-point detective with dispersion forces, dipoles and hydrogen bonds, steer a point around the phase diagrams of water and carbon dioxide, see why salt melts ice, and finish by separating mixtures yourself: tune a solvent to pull dyes apart on a chromatography plate and count the stages a still needs to purify a liquid.