One card for each practical: the idea, the steps, the numbers to know and the usual mistakes. Tap a card to open it.
Acid–Base Titration
You find an unknown concentration by adding a solution you know, a little at a time, until the two have just reacted.
Back Titration
When a solid will not titrate directly, you add a known excess of acid and then titrate the acid that is left over. The difference is the acid that reacted.
Double-Indicator Titration
One titration with two indicators gives two endpoints, V₁ and V₂, and from them you work out both parts of a mixture.
Redox Titration (KMnO₄)
This titration needs no indicator. Purple permanganate loses its colour as it reacts, and the endpoint is the first drop that leaves the flask pink.
Iodometric Titration
You set free brown iodine in the flask and titrate it with thiosulphate. Starch goes in only near the end.
Standard Solution Preparation
You work out the mass you need for a given concentration, weigh it, and make it up to an exact volume. Every titration depends on solutions made this way.
Qualitative Salt Analysis
You identify an unknown salt by how it reacts: the colour of the precipitate, the gas given off, and whether the precipitate dissolves in excess.
Gas Tests
Each common gas has one test of its own. Learn the gas, the test and the result together and you can name any of them.
Flame Tests
Hold a metal salt in a flame on a clean wire, and the colour of the flame tells you the metal.
Heating of Salts
You heat a salt, note any colour change, gas or water given off, and then write the equation for the decomposition.
Organic Functional Group Tests
A few quick tests with reagents tell you which functional group an organic compound has.
Food Substance Tests
There are four food tests, for sugar, starch, protein and fat, and each gives its own colour change.
Electrolysis
A current through a molten or dissolved ionic compound makes ions give up or take electrons at the electrodes. Reduction happens at the cathode and oxidation at the anode.
Chromatography
A solvent rises up the paper and carries the mixture with it. The parts that hold on to the paper less travel further, so they separate into spots.