Group 2

Group 2

Physical Properties
1. Melting points decrease down the group
  1. Atoms increase in size, outer electrons further away from nucleus and increased shielding= attractive force of nucleus on outer electrons decreases
2. Reactivity increases down the group
3. Ionisation energy decreases down the group
Chemial Properties
1. Reaction with water= M + 2H20 >>>> M(OH)2 + H2
  Annotations:
  - Where M is any metal Follows trend of reactivity
2. Solubilities of the hydroxides become more soluble down the group
3. Use of magnesium hydroxide= milk of magnesia- used in indigestion tablets to neutralise stomach acid
  Annotations:
  - Mg(OH)2
4. Use of calcium hydroxide- treat acidic soil in agriculture
  Annotations:
  - Ca(OH)2
5. Solubilities of the sulphates, opposite- less soluble down the group
6. sulphate ions test= e.g barium sulphate acidified and then barium chloride- if there is sulphate present it forms barium sulphate- the addition of the acid removes carbonate ions
  1. Ba+ + SO42- >>>>> BaSo4
7. Use of barium sulphate (BaS04)
  Annotations:
  - barium meal to outline the gut in x rays bc it is insoluble

Resource summary

	Created by Clodagh Mullins about 9 years ago