2.2 Group 2

Question 1

first ionisation energy equation of magnesium

Answer 1

Mg (g) -> Mg+ (g) + e-

Question 2

trend of ionisation energy down group 2

Answer 2

decreases.
atomic radius increases as there are more electron shells which also increases shielding.
less energy required for the outer electron to be removed

Question 3

trend of atomic radius down group 2

Answer 3

increases.
more electron shells.
increased shielding.
outer electrons are further away from the nucleus.
weaker electrostatic attraction.

Question 4

trend of melting point down group 2

Answer 4

decreases.
metallic bond gets weaker as you go down the group.
as atomic size increases.
the distance between the nucleus and the electrons gets bigger.
electrostatic force of attraction between positive ions and delocalised electrons gets weaker.
less energy required to break the bonds.

Question 5

reactivity down group 2

Answer 5

reactivity increases.
as electrons get further away from the nucleus.
easier to react with other elements.
form 2+ ions

Question 6

group 2 reactions with oxygen

Answer 6

solid white oxide forms
form MgO

Question 7

group 2 reactivity with water

Answer 7

reactivity increases down the group.
fizzing, metal dissolving and heating up of solution is observed.

Question 8

magnesium reaction with water + steam

Answer 8

water: produces magnesium hydroxide Mg(OH)2
slow reaction
steam: produces magnesium oxide MgO
burns with a bright white flame

Question 9

trend of solubility of hydroxides down group 2

Answer 9

solubility increases down the group.
Mg is insoluble + Ba is soluble.

Question 10

trend of solubility of sulfates down group 2

Answer 10

solubility decreases down the group.
magnesium is soluble
barium is insoluble

Question 11

magnesium in titanium

Answer 11

TiO2 is converted to TiCl4
TiCl4 is purified through fractional distillation
Ti is extracted by Mg

Question 12

equations for the extraction of titanium

Answer 12

1) TiO2 + 2Cl2 + 2C ->
TiCl4 + 2CO
2) TiCl4 + 2Mg ->
Ti + MgCl2

Question 13

use of magnesium hydroxide

Answer 13

used as an antacid to treat indigestion

Question 14

use and equation of calcium hydroxide

Answer 14

used to neutralise soil
Ca(OH)2 + 2HCl -> 2H2O + CaCl2

Question 15

use of calcium oxide and calcium carbonate + equations

Answer 15

remove SO2 from flue gases.
CaO + SO2 ->
CaSO3
CaCO3 + SO2 ->
CaSO3 + CO2

Question 16

use of barium sulfate

Answer 16

used to outline the gut in medical x-rays. used as it is insoluble

Question 17

test for sulfate ions

Answer 17

add HCl to sample.
add BaCl2
white precipitate will form if ions are present