8.1 Group 2

Question 1

reactivity ….. down group 2

and why

Answer 1

increases
* inonisation energy decreases
* beciuase atomic radius increases,
* increasing sheilding - cancels out eh increase in the nuclear charge
* therefore there is a decrease in attraction to the outer electrons and the nucleus

become stronger reducing agents

Question 2

what are the uses of group 2 elements?

Answer 2

• bases- ability to neutralise acids
• agriculture-to increase PH of the soil
• medicine- antacids to neutralise stomch acid

Question 3

in redox reactions group 2 elemets act as the ….. agent

Answer 3

reducing agent

Question 4

group 2 + H2O —–>

Answer 4

alkli hydroxide M(OH)2 + H2 (g)

Question 5

group 2 + acid

Answer 5

salt and hydrogen

Question 6

thermal decomposition

METAL CARBONATE + heat

Answer 6

METAL OXIDE + CARBON DIOXIDE

Question 7

Trend in ease of thermal decomposition:

Answer 7

Going down the group, group 2 carbonates become MORE DIFFICULT to decompose. They get more stable down the group

• Magnesium has a
  higher charge
  density.
• Pulls the electron
  density off the
  carbonate ion,
  making it easier to
  decompose.
• Bonds in carbonate
  ion are more
  susceptible to
  breaking

Question 8

Solubility of group 2 hydroxides:

Answer 8

• The solubility of the Group 2 hydroxides increases as you go down the Group.
• This means that as you go down Group 2 more hydroxide ions are formed (for the same amounts).
• This means that as you go down Group 2 the hydroxides become more alkaline.
• When the solution becomes saturated any more metal ions and hydroxide ions will form a precipitate. (as above)

Question 9

what are grp 2s physical properties?

Answer 9

• solid metals
• form white compounds
• high mp nd bp
• light metals-low density they float
• 2+ ions

Question 10

group 2 oxide + water –>

Answer 10

hydroxide ions + alkaline solutions