Group 2 (Alkaline Earth Metals)

Question 1

Explain the trend in first ionisation energy as you go down group 2

Answer 1

Decreases down group 2
Number of electron shells increases
Increased atomic radius
Weaker force between outer shell and nucleus
Less energy needed to remove electron

Question 2

Explain the trend in reactivity with water as you go down group 2

Answer 2

Increases down the group
Outer electrons further away from nucleus / more electron shielding
Electrons are more easily lost

Question 3

What is the trend in hydroxide solubility down the group?

Answer 3

Increases
Mg(OH)2 is insoluble
Ba(OH)2 is a strong alkaline solution

Question 4

What is the trend in sulfate solubility down the group?

Answer 4

Decreases
MgSO4 is soluble
BaSO4 is insoluble

Question 5

Explain the trend in melting point down group 2

Answer 5

Decreases down the group
Delocalised electrons further away from positive nucleus
Weaker metallic bonds which take less energy to weaken

Question 6

Write the equation for the extraction of titanium using magnesium

Answer 6

TiCl4 + 2Mg —> 2MgCl2 + Ti

Question 7

How can CaO and CaCO3 be used to remove flue gases with equations?

Answer 7

CaO + SO2 —> CaSO3
CaCO3 + SO2 —> CaSO3 + CO2

Question 8

What is magnesium hydroxide used in?

Answer 8

Antacid to treat indigestion

Question 9

What is barium sulfate used in?

Answer 9

Barium meals outline the gut through an X-ray
(barium sulfate isn’t toxic as its insoluble)

Question 10

How can barium sulfate be used to test for sulfate ions?

Answer 10

Add to HCl
White ppt forms if sulfate ions are present

Question 11

What is calcium hydroxide used for and write an equation to show this

Answer 11

Used to neutralise soil
Ca(OH)2 + HCl —> CaCl2 + 2 H2O