Chemistry A-Level Equilibria

Flashcards covering the key concepts and formulas related to equilibria and distribution coefficients.

Equilibria

The distribution of a solute between two immiscible systems, like ether and water.

Solute Distribution

When a solute is shaken with two immiscible solvents, it distributes itself until equilibrium is reached, with the concentration in each solvent remaining constant.

Distribution/Partition Coefficient (Kd)

The ratio of the concentrations of a solute in two immiscible solvents at equilibrium.

Kd Formula

Kd = [S]e / [S]w, where [S]e is the concentration of solute in ether and [S]w is the concentration of solute in water.

Kd Properties

An equilibrium constant that depends on temperature and the solubility of the solute in the two solvents; it is dimensionless (no units).

[S]e

me / ve

[S]w

mw / vw

Multiple Extractions

Increasing the efficiency of extraction, even if the total solvent volume remains the same.

Solvent Extraction

A purification technique where a substance is extracted from one solvent to another immiscible solvent, leaving impurities behind.

Iodine Solubility

Shows that iodine is much more soluble in tetrachloromethane than in water.