4. group 2 - the alkaline earth metals

Question 1

group 2 elements form __ ions

Answer 1

2+ ions

Question 2

does reactivity increase or decrease down group 2 ?

Answer 2

increase.

Question 3

why does reactivity increase down group 2

3 points

Answer 3

1. down group ionisation energies decrease. (increasing atomic radius and shielding affect)
2. when group 2 elements react they lose electrons forming + ions (cations).
3. easier it is to loose electrons (lower ionisation energy) more reactive the element.

Question 4

when group 2 elements react they are oxidised from state of 0 to

Answer 4

2+

Question 5

group 2 metals react with water to give

e.g. M(s) + 2H2O(l) ->

Answer 5

metal hydroxide and hydrogen

M(OH)2(aq) + H2(g)

Question 6

group 2 metals burn to form

e.g. 2M(s) + O2(g) ->

Answer 6

solid white oxides

2MO(s)

Question 7

group 2 metals react with acid to give

e.g.M(s) + 2HCl(aq) ->
metal + dilute hydrochloric acid

Answer 7

salt and hydrogen

e.g. MCl2(aq) + H2(g)
metal chloride and hydrogen

Question 8

group 2 oxides and hydroxides are

Answer 8

bases

Question 9

most group 2 oxides and hydroxides are soluble so are

Answer 9

alkalis

Question 10

1. oxides of group 2 react with water to form
2. e.g. CaO(s) + H2O(l) ->
3. what makes these solutions strongly alkaline PH 13-14
4. an exception to this is
5. why do the oxides form more strongly alkaline solutions as you go down the group?

Answer 10

1. metal hydroxides which dissolve
2. Ca2+(aq) + 2OH-(aq)
3. hydroxide ions OH-
4. MgO magnesium oxide. reacts slowly and hydroxide isn’t very soluble.
5. hydroxides get more soluble.

Question 11

group 2 elements are known as

Answer 11

the alkaline earth metals

Question 12

what are many of the common compounds of group 2 used for

Answer 12

neutralising acids

Question 13

e.g of  group 2 elements neutralising acids.
calcium hydroxide (slaked lime Ca(OH)2) is used in

Answer 13

agriculture to neutralise acidic soils

Question 14

e.g of group 2 elements neutralising acids.

magnesium hydroxide Mg(OH)2 and calcium carbonate CaCO3 are used in

Answer 14

some indigestion tablets as antacids

Question 15

ionic equation for neutralisation

Answer 15

H+(aq) + OH-(aq) -> H2O(l)