Group 2

Question 1

Explain the trend in atomic radius down group 2

Answer 1

Increases because there are more shells

Question 2

Explain the trend in ionisation energy down group 2

Answer 2

Decreases -Extra shells -Less FoA because positive nucleus and negative e- are further away - Less energy to remove outer e-

Question 3

Explain the trend in mpt/bpt down group 2

Answer 3

Decreases: -Strength of metallic bonding decreases -Size of atoms/atomic radius increases -Positive nuclei further away from neg e- - Lower charge density - Less energy to overcome FoA

Question 4

Are group 2 metals oxidised or reduced?

Answer 4

Oxidised

Question 5

Does reactivity increase or decrease down group 2?

Answer 5

Increases

Question 6

What is milk of magnesia and what is it used for?

Answer 6

Magnesium hydroxide Indigestion remedy to neutralise excess stomach acid

Question 7

What is the equation for the reaction of magnesium with cold water?

Answer 7

Mg(s) + H2O(l) Mg(OH)2(s) + H2(g)

Question 8

What is the chemical name for slaked lime and what is it used for?

Answer 8

Calcium hydroxide -to neutralise acidic soil (after acid rain)

Question 9

Does solubility of G2 hydroxides increase or decrease down group 2?

Answer 9

Increases

Question 10

What do group 2 hydroxides look like?

Answer 10

White solids

Question 11

Why is milk of magnesia sold as a suspension in water rather than a solution?

Answer 11

Magnesium hydroxide is almost insoluble

Question 12

How is the solubility of calcium hydroxide described and what is it used for?

Answer 12

Sparingly soluble lime water

Question 13

What is the equation for the reaction of magnesium with steam?

Answer 13

Mg(s) + H2O(l) MgO(s) + H2(g)

Question 14

Explain the difference between the products produced when a group 2 metal reacts with cold water and when it reacts with steam

Answer 14

Cold water = hydroxide Steam = oxide Metal hydroxides thermally decompose (split up on heating) to give the oxide and water.

Question 15

What is the pH of the magnesium hydroxide formed when Mg and water react?

Answer 15

8-9 (weak alkaline)

Question 16

What is the pH of the barium hydroxide formed when Mg and water react?

Answer 16

13-14 (strong alkaline)

Question 17

Does solubility of G2 sulfates increase or decrease down group 2?

Answer 17

Decreases

Question 18

Why can you swallow barium sulfate when barium is highly toxic?

Answer 18

Barium sulfate is insoluble

Question 19

Why is barium sulfate good for medical X-rays?

Answer 19

The heavy barium atom is very good at absorbing -rays

Question 20

How do use barium sulfate you test for sulfate ions in a solution?

Answer 20

• Acidify solution with nitric/hydrochloric acid - Add barium sulfate - White ppt formed if sulfate is present

Question 21

What is the half equation for the formation of barium sulfate?

Answer 21

Ba²⁺ (aq) + SO₄^2-(aq) ——> BaSO₄(s)

Question 22

How does the barium test for sulfate ions distinguish between barium sulfate and barium carbonate (also a white ppt)?

Answer 22

The addition of the acid removes carbonate ions as caron dioxide