Inorganic Chemistry- Group 2

Question 1

Bonds of Group 2

Answer 1

High melting point
Giant metallic structure
Strong metallic bonds
Strong attraction between the delocalised electrons and the positive metal ions
Requires a lot of energy to remove

Question 2

Density of Group 2

Answer 2

They are dense than group 1 metals
They are a greater charged ion than group 1 metals
They are held closely

Question 3

Reactivity of Group 2

Answer 3

Similar reactivities
They have the same number of electrons in their outer shell

Question 4

Atomic Radius of Group 2

Answer 4

Increases as you go down the group
More shielding/shells
Weaker nuclear attraction between the outer shell and the nucleus
Held less tightly

Question 5

First Ionisation Energy of Group 2

Answer 5

Decreases as you go down the group
More shielding/shells
Weaker nuclear attraction between the outer shell and the nucleus
Less energy is required to remove the electron

Question 6

Melting point of Group 2

Answer 6

Decreases as you go down the group
More shielding/shells
Weaker nuclear attraction between the outer shell and the nucleus
Metallic bonds get weaker

Question 7

Reactivity of Group 2 electrons

Answer 7

Increases as you go down the group
More shielding/shells
Weaker nuclear attraction between the outer shell and the nucleus
so e- is more easily lost

Question 8

Reaction of magnesium with cold water
Observation
Equation

Answer 8

Observation: very slow reaction with few bubbles
Equation: Mg(s) + 2H2O(l) -> Mg(OH)2(s) + H2(g)

Question 9

Reaction of magnesium with steam
Observation
Equation

Answer 9

Observation: bright white light, white powder/solid
Equation: Mg(s) + H2O(l) -> MgO(s) + H2(g)

Question 10

Reaction of calcium with water
Observation
Equation

Answer 10

Observation: effervescence, white solid
Equation: Ca(s) + H2O(l) -> Ca(OH)2(aq) + H2(g)

Question 11

Reaction of strontium with water
Observation
Equation

Answer 11

Observation: effervescence, white solid
Equation: Sr(s) + H2O(l) -> Sr(OH)2(aq) + H2(g)

Question 12

Reaction of barium with water
Observation
Equation

Answer 12

Observation: effervescence, colourless solution
Equation: Ba(s) + H2O(l) -> Ba(OH)2(aq) + H2(g)

Question 13

How is titanium extracted from its ore?

Answer 13

TiO2 + 2Cl2 + 2C -> TiCl4 + 2CO

Question 14

How is titanium chloride separated?

Answer 14

TiCl4 + Mg -> Ti + MgCl2

Question 15

Solubility of Group 2 hydroxides

Answer 15

Mg(OH)2- sparingly soluble
Ca(OH)2
Sr(OH)2
Ba(OH)2- soluble

Question 16

Use of magnesium hydroxide in medicine

Answer 16

Antacid

Question 17

Use of calcium hydroxide in agriculture

Answer 17

Neutralise acidic soil

Question 18

Solubility of Group 2 sulfates

Answer 18

MgSO4- soluble
CaSO4- sparingly soluble
SrSO4
BaSO4- insoluble

Question 19

How to confirm the presence of Mg2+ ions?

Answer 19

Add sodium hydroxide solution
Mg(OH)2 = sparingly soluble = thick white precipitate = slightly alkaline

Question 20

How to confirm the presence of Ba2+ ions?

Answer 20

Add sulfuric acid
BaSO4 = insoluble = thick white precipitate

Question 21

Test for BaSO4

Answer 21

Add 1cm3 dilute HCl to 1cm3 unknown solution
Add 1cm3 BaCl2
Positive result- precipitate formed

Question 22

Why do we add HCl to SO4 test?

Answer 22

To remove any ions that could interfere with the test