Group 2

Question 1

Why are group 2 metals in the S block of the periodic table?

Answer 1

The outer electron is in the s subshell

Question 2

Why does the 1st ionisation energy of group 2 metal decreases down the group?

Answer 2

Atomic radius increases
More shielding down group 2
Weaker attraction between nucleus and outer electrons

Question 3

How does melting point change down group 2 (from calcium to barium)?

Answer 3

Decreases

Question 4

Explain why calcium has a higher melting point than barium?

Answer 4

Barium has larger ions
Metallic bonds are weaker down the group and are more easily overcome
Weaker attraction between sea of delocalised electron and metal ions
So melting point decreases down group 2

Question 5

How does reactivity change down group 2?

Answer 5

Increases down group 2

Question 6

Group 2 metals react with water to form what two substances?

Answer 6

Metal hydroxide(aq) + H2(g)

Question 7

Use of Mg(OH)2

Answer 7

Used as an indigestion remedy to neutralise stomach acid

Question 8

Group 2 metals react with steam to form what two substances?

Answer 8

Metal oxides(s) + H2(g)

Question 9

Group 2 oxides and hydroxides form what?

Answer 9

White solids

Question 10

How does the solubility of group 2 metal hydroxide changes down the group?

Answer 10

Increases

Question 11

How soluble is Mg(OH)2

Answer 11

Sparingly soluble

Question 12

How soluble is Ba(OH)2

Answer 12

Completely dissolves

Question 13

Group 2 metals react with H2SO4 to form what?

Answer 13

Metal sulphates

Question 14

How does the solubility of group 2 sulphates change down the group?

Answer 14

Decreases

Question 15

How soluble is BaSO4?

Answer 15

Insoluble

Question 16

Use of barium sulphate?

Answer 16

Feeding the patient a barium metal
Absorbs X-rays
Digestive system can be seen

Question 17

Why is barium sulphate safe to feed to patients even though it is highly toxic?

Answer 17

Insoluble so cannot dissolve and pass through cell membranes into body tissue

Question 18

Test for sulphate ions (SO42-)

Answer 18

Add BaCl2
White precipitate

Question 19

Why is BaCl2 used to test for sulphate ions?

Answer 19

The sulphate ions displace the chloride ions, forming the insoluble salt barium sulphate

Question 20

Why is acidified BaCl2 solution to test for sulphate ions (2)

Answer 20

Acidified with hydrochloric acid
This is needed to react with carbonate impurities that are often found in salts which would form a white Barium carbonate precipitate and so give a false result

Question 21

Write the equations for extraction of titanium using magnesium (2)

Answer 21

TiO2 + 2Cl2 + C —> TiCl4 + CO2
TiCl4 + 2Mg —> 2MgCl2 + Ti

Question 22

What is Ca(OH)2 used for
Write an equation for this (2)

Answer 22

To neutralise soil
Ca(OH)2 + 2HCl –> 2H2O + CaCl2

Question 23

What are flue gases (2)

Answer 23

Gases given out by power stations
Which are harmful to the environment

Question 24

Two methods of desulphurisation (2)

Answer 24

CaO(s) + 2H2O(l) + SO2(g) + 0.5 O2 –> CaSO4.2H2O(s)

CaCO3(s) + 0.5 O2(g) + SO2(g) –> CaSO4(s) + CO2(g)