GROUP 2

Question 1

trend in atomic radius

Answer 1

increases down the group
more protons more shells= bigger radius

Question 2

trend in first ionisation energy

Answer 2

decreases down the group
atomic radius increases, more shielding effective nuclear attraction decreases easier to lose electron

Question 3

trend in melting point

Answer 3

decreases down the group
atomic radius increases therefore more shielding so effective nuclear attraction decreases
easier to lose electrons

Question 4

Be- reaction with water

Answer 4

no reaction with water and steam

Question 5

Mg- reaction with water

Answer 5

no reaction, slow with cold water
burns with white flame
forms white powder with steam

M(s)+ H2O(g)—> MgO(S)+H2(g)

Question 6

Ca- reaction with water

Answer 6

fizzes in water, forms colourless solution
Ca(s)+ 2H2O(g)—> Ca(OH)2(aq)+H2(g)

Question 7

Sr/Ba- reaction with water

Answer 7

stored in oil
fizzes in water forms colourless solution
Sr(s)+ 2H2O(g)—> Sr(OH)2(aq)+H2(g)

Question 8

trend in reactivity sown the group

Answer 8

increases down the group

when metals react, lose their outer 2 electrons down the group, atoms become bigger= more shielding

weaker attraction between the nucleus and outer shell electrons so outer shell electrons are more easily lost

Question 9

trend in solubility of group 2 hydroxides

Answer 9

solubility increases down the group

Question 10

uses of group 2 hydroxides

Answer 10

Mg(OH)2- milk of magnesia
neutralises HCL stomach acid

Mg(OH)2+ 2HCL—> MgCl2 + 2H2O

Ca(OH)2- slaked lime
agriculture
decreases soil acidity
improves crop yield

Question 11

solubility of group 2 sulphates

Answer 11

decreases down the group

Question 12

uses of group 2 sulphates

Answer 12

BaSO4- medicine
patient given barium meal
insoluble so can pass through body without dissolving any bodily fluids can absorb x-ray

Question 13

identifying sulphates using barium chloride

Answer 13

Barium sulphate is insoluble
if the solutions containing barium ions and sulphate ions are mixed a white precipitate of barium sulphate is formed

barium chloride is soluble so it is used to provide a source of barium ions

Question 14

explain how titanium is extracted from the ore (TiO2)

Answer 14

1) TiO2 —> TiCl4 by heating with carbon and chlorine

2)TiCl4 passes through fractional distillation to increase the impurity

3) reduce the TiCl4 with Mg in furnace at 1000 degrees

TiCl4 + 2Mg—> Ti+ 2MgCl2