2.2 Group 2, the alkaline, earth metals

Question 1

Why are are group 2 metals reffered to as the alkaline earth metals?

Answer 1

Because their oxides and hydroxides are alkaline

Question 2

What is the trend for melting points as you go down group 2 and why?

Answer 2

The melting points decrease as they all form metallic structures with 2+ ions. This means the larger ions have the same charge meaning they have a smaller charge desinity creating smaller electromagetic forces between the ions and electrons.

Question 3

What is the trend for ionisation energies down group 2 and why?

Answer 3

Ionisation energies decrease down the group as there is more electron shielding between the nucleus and the outer shell electrons meaning the positive influence is acting further away.

Question 4

What is the general trend of reactivitly going down group 2?

Answer 4

Reactivity increases down the group

Question 5

What is another name for magnisium hydroxide and what are its uses?

Answer 5

Milk of magnisia and is used to neutralise stomach acid which causes intergestion, heartburn and wind.

Question 6

Using M as a metal, name 2 compounds formed when group 2 metals react with water

Answer 6

M(OH)₂(aq)

MO(s)

Question 7

What is the use of calcium hydroxide?

Answer 7

To neutralise soils for certain crops to grow better

Question 8

What is the general trend for solubilty of group 2 hydroxides going down the group?

Answer 8

Solubilty increases down the group

Question 9

What is the general trend for solubilty of group 2 sulphates going down the group?

Answer 9

Solubility decreases down the group

Question 10

Explain how barium sulphate can indicate the presence of sulphate ions in a solution describing each step

Answer 10

1. Add nitric or hydrochloric acid to the solution to react off any carbonate ions which also form a white precipitate with barium
2. Add barium chloride solution to the solution being tested, the barium will form a white precipitate with the sulphate ions which is practically insoluble