GROUP 2

Question 1

what happens to atomic radius down group 2

Answer 1

increases down the group so more shells

Question 2

what happens to 1st ionisation energy down the group

Answer 2

decreases down the group
more shielding
easier to lose electron

Question 3

what happens to reactivity down the group

Answer 3

increases down the group
more shielding
easier to lose electrons to form positive ions

Question 4

what happens to melting point down group 2

Answer 4

decreases down the group
more shielding
delocalised electron further from the nucleus
less attraction between positive ions and delocalised electrons
weaker metallic bonding

Question 5

solubility of hydroxides

Answer 5

magnesium hydroxide - sparingly soluble
calcium hydroxide - slightly soluble
strontium hydroxide - soluble
barium hydroxide - soluble

Question 6

uses of hydroxide

Answer 6

magnesium hydroxide - in medicine for stomach problems
calcium hydroxide - in agriculture to neutralise acid soil (slaked lime)

Question 7

solubility of sulphates

Answer 7

magnesium sulphate - soluble
calcium suplhate - slightly soluble
strontium sulphate - insoluble
barium sulphate - insoluble

Question 8

barium meal

Answer 8

BaSO4 absorbs x rays so the outline of the gut can be seen
Ba2+ ions are very toxic
the technique is harmless because barium sulphate is completely insoluble

Question 9

describe the test for sulphates

Answer 9

1. add Hcl to remove unwanted ions]
2. add barium chloride solution
   sulphates give a white precipitate