3.1.2 - Group 2

Question 1

What happens to the atomic radius as we go down group 2 ?

Answer 1

Atomic radius increases

Question 2

What happens to the 1st isolation energy and reactivity as we go down group 2 and why ?

Answer 2

1st ionisation energy decreases and reactivity increases.

Question 3

Electron configuration for elements in group 2

Answer 3

Question 4

Group 2 reactions with water.

Answer 4

Metal + Water = Metal Hydroxide + Hydrogen

Basic set up:
x(metal)(s) + 2H2O(l) -> x(OH)2 (aq) + H2(g)

Question 5

what happens when magnesium reacts with steam ?

Answer 5

It produces a magnesium oxide instead of hydroxide.

• The white solid made is magnesium oxide.

mg2 + H2O -> mgO + H2

Question 6

Group to elements with Oxygen ?

Answer 6

The form bases (proton acceptors)

Question 7

How is a group 2 metal oxide produce and what happens when it reacts with water

Answer 7

• Reaction with group 2 metal and oxygen to form metal oxide (a base).
• The metal oxide reacts with water to produce a metal hydroxide.

Question 8

Group 2 hydroxides with dilute HCL

Answer 8

Just replace the H2 with the group 2 metals and add 2 next to the Cl
- Its Neutralisation reaction as water is produced

Question 9

Group 2 hydroxides with H2SO4

Answer 9

Just replace the H2 with the group 2 metals
- Its Neutralisation reaction as water is produced

Question 10

Group 2 carbonate with dilute HCL and H2SO4

Answer 10

Its just like the carbonate + acid reaction where CO2 is a product also.
Use the reaction withe hydroxide and dilute acid to help you also.

Question 11

Group 2 metals with Halogen

Answer 11

Question 12

Solubility and alkaniitly of group 2 hydroxides.

Answer 12

Question 13

solubility of group 2 sulphates

Answer 13

decrease down the group.

Question 14

Uses of group 2 compounds

Answer 14

Calcium hydroxide (limewater) = Nutralise acidic soils

Magnesium hydroxide and Calcium carbonate (CaCO3) - antacids = nutralise excess stomach acids.

Question 15

Try and explain the trend in solubility.

Answer 15

• Solubility increases as you move down the group 2 (metal hydroxides).
• This is because the size of the metal ions increase
• This causes the ionic bonds between the metal ions and the hydroxide ions become weaker. (Mg+ —- OH- weaker bond)
• So the metal ions start formings bonds with water molecules as well.
• Additionally OH- ions are polar so they form hydrogen bonds with water further enhancing the solubility of the metal hydroxide.