Inorganic Chemistry | Group 17

melting and boiling points

melting and boiling points

• increase

• molecule size increase

• number of electrons increase, stronger van der waals forces

radii

increase

new shell added

E.N.

decrease, electrons added and shielding increases

colour

• F - yellow

• Cl - yellow brown

• Br - red-brown / yellow

• I - grey black

• At - black

reaction with H₂

halogen + hydrogen = halide

F = explosion and Cl = vigorous

Thermal stability

heated HF adn HCl not decomposed but HI does = purple gas

strength of halide bond decreases

reaction of silver ions and ammonia

• AgF - colourless

• AgCl - white

• AgBr - cream

• AgI - yellow

reaction with sulfuric acid

cold and solid

hydrogen halide given

NaCl + H2SO4 ⟶ HCl + NaHSO4

reaction with H2SO4

if oxidising agent

HBr + H2SO4 ⟶ H2O+ Br2 + O2

not strong enough for F and Cl

Cl reaction with NaOH

redox and disproportionation reaction

cl is both oxidised and reduces at the same time

cold: Cl2 + NaOH ⟶ NaCl + NaOCl + H2O

hot: 3Cl2 + 6NaOH ⟶ 5NaCl + NaOCl3 + 3H2O

chlorination: Cl + H2O ⟶ OCl^– + HOCl