Group 2

Question 1

General reaction formula between group 2 metal and oxygen
(M= metal)

Answer 1

2M(s) + O2(g) -> 2MO(s)

Question 2

General reaction formula between Sr/Ba and oxygen to form metal PEROXIDE
(M= metal)

Answer 2

M(s) + O2 -> MO2(s)

Question 3

General reaction formula between group 2 metal and water, as well as the exceptions for solubility (aq)
(M= metal)

Answer 3

M(s) + 2H2O(l) -> M(OH)2 (s) + H2(g)
Sr and Ba hydroxides are aqueous

Question 4

2 different reactions for Mg + H2O

Answer 4

Mg(s) + 2H2O(l) -> Mg(OH)2 (s) + H2(g)
and
Mg(s) + H2O -> MgO(s) + H2(g)

Question 5

General reaction formula between group 2 metal and dilute HCl
(M= metal)

Answer 5

M(s) + 2HCl(aq) -> MCl2(aq) + H2(g)

Question 6

General reaction formula between group 2 metal and dilute H2SO4, as well as the exceptions to solubility (aq)
(M= metal)

Answer 6

M(s) + H2SO4(aq) -> MSO4 (s) + H2(g)
Mg sulfate is sparingly soluble (aq)

Question 7

pH trend of group 2 OXIDES

Answer 7

Oxides are more basic down the group.
* More soluble and dissociates in water
MO(s) + H2O(l) -> M2+ + 2OH-

Question 8

General reaction formula between group 2 OXIDE and water
(M= metal)

Answer 8

MO(s) + H2O(l) -> M(OH)2 (s)

Question 9

General reaction formula between group 2 OXIDE and dilute HCl
(M= metal)

Answer 9

MO(s) +2HCl(aq) -> MCl2(aq) + H2O(l)

Question 10

General reaction formula between group 2 OXIDE and dilute H2SO4
(M= metal)

Answer 10

MO(s) + H2SO4(aq) -> MSO4(s) + H2O(l)

• Mg sulfate is sparingly soluble

Question 11

Solubility trend of group 2 SULFATES

Answer 11

Decrease in solubility down the group

Question 12

Which group 2 CARBONATE is soluble?

Answer 12

BeCO3

Question 13

General reaction formula between group 2 CARBONATE and dilute HCl
(M= metal)

Answer 13

MCO3(s) + 2HCl(aq) -> MCl2(aq) + H2O(l) + CO2(g)

Question 14

General reaction formula between group 2 CARBONATE and dilute H2SO4
(M= metal)

Answer 14

MCO3(s) + H2SO4(aq) -> MSO4(s) + H2O(l) + CO2(g)

• Mg sulfate is sparingly soluble

Question 15

General reaction formula of group 2 CARBONATE thermal decomposition
(M= metal)

Answer 15

MCO3(s) + O2(g) -> MO(s) + CO2(g)

Question 16

General reaction formula of group 2 NITRATE thermal decomposition
(M= metal)

Answer 16

2 M(NO3)2 (s) -> 2MO(s) + 4NO2 (g) + O2 (g)

Question 17

Thermal stability trend of CO3 and NO3, with reasoning.

Answer 17

Down the group, CO3 and NO3 thermal stability increases.
Down the group, cations get bigger and less polarising of the anion. More polarisation causes the bond to become more covalent (sharing electrons) than ionic, lowering the bond strength.

Question 18

Nature of group 2 ions

Answer 18

Reducing agents (donates 2 outer electrons) and are oxidised (+2)

Question 19

Reactivity trend of group 2 metals, with reasoning.

Answer 19

Reactivity increases down the group.
Nuclear charge increases, but valence electrons are added to higher principle quantum shells, increases shielding. Down the group, easier to lose electrons and more vigorous reactions.

Question 20

Ionisation energy trend of group 2 metals, with reasoning.

Answer 20

IE decreases down the group.
Nuclear charge increases, but valence electrons are added to higher principle quantum shells, increases shielding. Down the group, easier to lose electrons so less energy needed.

Question 21

Atomic radius trend of group 2 metals, with reasoning.

Answer 21

Atomic radius increases down the group due to increase in quantum principle shells.

Question 21

Melting point trend of group 2 metals, with reasoning.

Answer 21

Melting point decreases down the group due to increasing atomic radius, causing further distance between nucleus and electrons, weakening attraction.

Question 22

Density trend of group 2 metals.

Answer 22

Density increases down the group.