Group 2

Question 1

what block are group 2 elements?

Answer 1

s block

Question 2

what are group 2 elements called?

Answer 2

alkaline earth metals

Question 3

what are the most common types of reactions for group 2 elements?

Answer 3

redox reactions, lose 2 electrons to form 2+ ions

Question 4

are group 2 elements reduced or oxidised?

Answer 4

oxidised

Question 5

what type of agents are group 2 elements?

Answer 5

reducing agents

Question 6

what is produced when group 2 reacts with oxygen?

Answer 6

metal oxide

Question 7

what is produced when group 2 elements reacts with water?

Answer 7

metal hydroxide and hydrogen

Question 8

what is produced when group 2 reacts with dilute acids?

Answer 8

salt and hydrogen

Question 9

what happens to reactivity of group 2 elements as you go down the group?

Answer 9

reactivity increases
- atomic radius and electron shielding increases (number of electrons increases)
- nuclear attraction between outer electrons and nucleus weakens
- greater nuclear charge
- ionisation energies decrease
- easier to lose 2 electrons from highest energy shell

Question 10

what is the outer shell electron configuration of group 2 elements?

Answer 10

s2

Question 11

what is formed when group 2 oxides react with water?

Answer 11

metal hydroxides

Question 12

what happens to the solubility of the hydroxides as you go down the group 2?

Answer 12

• the solubility increases
• the solutions contain more OH- ions (increased concentration) and are therefore more alkaline as pH increases

Question 13

what pH does Mg(OH)2 have?

Answer 13

10

Question 14

what pH does Ba(OH)2 have?

Answer 14

13

Question 15

what are the uses of group 2 compounds as bases?

Answer 15

• Ca(OH)2 in agriculture
• Mg(OH)2 and CaCO3 as antacids in treating indigestion

Question 16

how is Ca(OH)2 used in agriculture?

Answer 16

Ca(OH)2 is added to fields to neutralise the acid soils (by increasing pH) , forms neutral water

Question 17

how are Mg(OH)2 and CaCO3 used in treating indigestion?

Answer 17

hydrochloric acid in the stomach and neutralisation can take place between the HCl and Mg(OH)2 and CaCO3

Question 18

what happens to the first ionisation energies in group 2 elements as you go down the group?

Answer 18

• 1st ionisation energies decreases
• atomic radius and electron shielding increases
• weaker nuclear attraction
• greater nuclear charge
• so less energy required to remove one mole of electrons

Question 19

what type of agents are group 2 elements?

Answer 19

reducing agents

Question 20

why are group 2 elements reducing agents?

Answer 20

because it helps another species to get reduced by donating its electrons

Question 21

what are redox reactions?

Answer 21

electrons are transferred between 2 species
- oxidation and reduction are taking place

Question 22

what happens to the second ionisation energies as you go down the group?

Answer 22

they decrease

Question 23

what is the equation for Ca(OH)2 in agriculture?

Answer 23

Ca(OH)2(s) + 2H+(aq) –> Ca2+(aq) + 2H2O(l)

• acid = H+

Question 24

what is the equation for Mg(OH)2 as antacids?

Answer 24

Mg(OH)2(s) + 2HCl(aq) –> MgCl2(aq) + 2H2O(l)

Question 25

what is the equation for CaCO3 as antacids?

Answer 25

CaCO3(s) + 2HCl(aq) --> CaCl2(aq) + H2O(l) + CO2(g)