redox reactions and reactivity of Group 2 metals Flashcards
what do the group 2 elements form?
2+ ions
what is the outer electron configuration for group 2 elements?
s2
state the trend in atomic radius down the group
increases
state the trend in ionisation energy down the group
decreases
describe the trend in reactivity down the group
- increases
- due to increased shielding and atomic radius
- weaker nuclear attraction
describe the reaction of group 2 elements with water
- forms metal hydroxides + hydrogen
- reactivity increases down group
- Mg reacts vigourously with steam
describe the reaction of group 2 elements with oxygen
- forms metal oxides
- white solids
when steam is used, what colour flame does magnesium burn with?
bright white flame
to form hydrogen and magnesium oxide (white powder)
describe the trend in alkalinity down the group
- increases
- as solubility increases
state the reaction between group 2 oxides and hydroxides
neutralisation
state the use of a group 2 hydroxide
- calcium hydroxide neutralises acidic soil
- magnesium hydroxide neutralises excess stomach acid
describe the reaction of group 2 metals with dilute acids
forms bubbles of hydrogen gas + solutions of metal compounds
describe what happens to solubility of group 2 hydroxides as you go down group 2
increases
due to their solubilities, what are the uses of Mg(OH)2 + Ba(OH)2?
Ca(OH)2 in agriculture to neutralise acid
soils
Mg(OH)2 and CaCO3 as ‘antacids’ in treating
indigestion
describe what happens to the solubility of group 2 sulphates as you go down group 2? and the uses ?
decreases
- insolubility of barium sulphate means its useful in medicine as barium meals - tracer
barium chloride is used as a test for sulphate ions as it forms a white ppt
