3.2 - Group 2

Question 1

What do group 2 elements act as (redox)?

Answer 1

reducing agents

Question 2

Trend in reactivity down group 2

Answer 2

increases because:
- atomic radius increases
- shielding increases
- nuclear attraction decreases
- IE decreases

Question 3

Trend in solubility down group 2 (for hydroxides they form)

Answer 3

increases because:
- more OH- ions = more alkaline (higher pH)

Question 4

Group 2 compounds and their uses

Answer 4

• Ca(OH)2: neutralises acidic soils
• Mg(OH)2 and CaCO3 are ‘antacids’ = treat indigestion

Question 5

Metal + O2

Answer 5

metal oxide

Question 6

Metal + H2O

Answer 6

metal hydroxide + hydrogen

Question 7

Metal + acid

Answer 7

salt + hydrogen

Question 8

Metal oxide + H2O

Answer 8

metal hydroxide

Question 9

Observation when adding metal to excess of water

Answer 9

• effervescence
• solid dissolves

Question 10

Reaction of metal carbonate to metal oxide equation, type and conditions

Answer 10

• heat
• CaCO3 -> CaO + CO2
• type: thermal decomposition

Question 11

Change in observation of reaction if less reactive metal used

Answer 11

• less vigorous effervescence
• dissolves more slowly
• solution has lower pH/less alkaline
• ppt. forms/less soluble

Question 12

NB: calculating concentration of __ ions in solution

Answer 12

if e.g Sr(OH)2 and finding OH- ions multiply conc. by 2 because 2OH- present