1. Group 2 slap Mg(OH) 2 BaCl 2 /HCl H 2 sulfates base alkali CaO steam Mg(OH) 2 BaCl 2 /HCl H 2 sulfates base alkali CaO steam magnesium + _________  magnesium oxide + hydrogen Less soulble down group 2 Doesn’t neutralise sulfuric acidNeutralises acid OH - Thick white precipitate demonstrates presence of sulfate ion Formed when barium reacts with water Insoluble in water; neutralises acid

2. Thermal stability experiments Stability of carbonates (MCO 3 ) –Spatula of group 2 carbonate in a test tube –Clamp tube at a slight angle –Delivery tube into a tube containing about 1 cm depth limewater –Heat solid strongly –Take care when heating stops – remove limewater Stability of nitrates (M(NO 3 ) 2 ) –Spatula of group 2 nitrate in a test tube –IN FUME CUPBOARD: heat strongly –Test gases with glowing splint and starch/iodide paper

3. Thermal Stability Thermal stability increases down groups Anions decompose because of polarisation by cations High charge density (on cation) = unstable compound Mg 2+ Ba 2+

4. Thermal Stability Carbonates Group 1 (except Li) stable Group 2 (& Li) decompose on heating: CaCO 3  CaO + CO 2 ; Li 2 CO 3  Li 2 O + CO 2 (BaCO 3 is pretty stable – big ion = low charge density) Nitrates Group 1 (except Li) 2 NaNO 3  2 NaNO 2 + O 2 Group 2 (& Li) 2 Ca(NO 3 ) 2  2 CaO + 4 NO 2 + O 2 4 LiNO 3  2 Li 2 O + 4 NO 2 + O 2 Why do the lithium compounds behave as if lithium is in group 2?