Halide ions with sulphuric acid

Halogens —>(reduced) —> Halide ions

F-

Cl-

Br-

I-

Halogens = good oxidising agent

gains electrons easily

smaller atomic radius

less electron shielding

Good reducing agent

loses electrons easily

bigger atomic radius

more electron shielding

fluroide and chloride

bad reducing agent

General Acid + Base

Bromide and iodide

Good reducing agent

Reduction + oxidation (redox)

sodium fluroide + conc. H2SO4

NaF + H2SO4 —> NaHSO4 + HF

steamy fumes —> Hydrogen fluoride

these fumes would turn damp blue litmus paper red

sodium chloride + conc H2SO4

NaCl + H2SO4 —> NaHSO4 + HCl

white fumes - Hydrogen chloride gas

sodium bromide + conc H2SO4

2NaBr + 3H2SO4 —> 2NaHSO4 + SO2 + 2H2O + Br2

brown or orange fumes - bromine

choking fumes - sulphur dioxide

sodium iodide + conc H2SO4

8NaI + 9H2SO4 —> 8NaHSO4 + H2S + 4I2 +4H2O

purple gas/ vapor - iodine

white solid changes to black or solid - iodine

bad egg smell - hydrogen sulphide