Half Equation and observation

Half equation Observation Fe2+ Fe3+ The green solution turns brown (yellow/brownish-yellow/brown depends on the

concentration of the solution).

Fe3+ Fe2+ Brown solution turns green.

Cl2 Cl- Yellow solution is turns colourless. (If gas is used: Greenish-yellow gas is decolourized)

Br2 Br- Brown bromine water turns colourless(If bromine liquid is used: Brown bromine liquid is turns colourless)

Br- Br2 Colourless solution turns brown I- I2 Colourless solution turns brown (yellow/brownish-yellow/ brown depends on the

concentration of solution).

MnO42- Purple solution turns colourless

Cr2O72- Orange solution turns green.

Cu Cu2+ Copper plate dissolves/corrodes/becomes thinner.• Colourless solution turns blue/The intensity of the blue solution increases

Cu2+ Cu A brown solid is formed.• The blue solution turns colourless / paler.

Metals other than copper Zn Zn2+

Mg Mg2+

Zinc pieces or magnesium ribbon dissolves/corrodes/ becomes thinner.

Ag+ Ag A shiny grey solid forms.

Type of reaction NoteRedox Change of Fe2+ to Fe3+ / Change of Fe3+ to Fe2+

Displacement of metal from its salt solution Displacement of halogen from its halide solution Transfer of electron at a distance Reaction in electrolytic and chemical cells Rusting Extraction of metals

Non- redox- oxidation numbers of all elements are the same

Neutralisation Double decomposition Esterification Decomposition of carbonate salts

Oxidising agent Reducing agentChlorine water Potassium iodide , KIBromine water Potassium bromide , KBrAcidified potassium manganate (VII) solution

Reactive metals , Mg , Zn , Al

Acidified potassium dichromate (VI) solution

Salt solution , Fe 2+

Salt solution , Fe 3+