12. Experimental Techniques & Chemical Analysis

Apparatus for Measurement Different pieces of apparatus are used to measure time, temperature, mass and volume, depending on how precise the measurement needs…

Solute, Solvent and Solution Solute: a substance that is dissolved in a solvent Solvent: a substance that dissolves a solute Solution: a mixture of one or more…

What is a Titration? A titration is a technique used to find the volume of one solution that exactly reacts with a measured volume of another - for example, to…

What is Paper Chromatography? Paper chromatography is used to separate a mixture of soluble, coloured substances (such as the dyes in ink) using a suitable…

Locating Agents (Supplement) Paper chromatography can also separate mixtures of soluble colourless substances, using a suitable solvent and a locating agent . A…

Choosing a Method Which separation or purification technique is suitable depends on the properties of the substances in the mixture - whether they are soluble,…

Tests for Anions An anion is a negatively charged ion. Each anion below is identified by a specific chemical test. Anion Test Positive Result Carbonate, CO₃²⁻…

Testing Cations with Sodium Hydroxide and Ammonia A cation is a positively charged ion. Most metal cations are identified by adding aqueous sodium hydroxide…

Tests for Gases Gas Test Positive Result Ammonia, NH₃ Hold damp red litmus paper in the gas Turns blue Carbon dioxide, CO₂ Bubble through limewater Limewater…