Group 2

Question 1

What are the elements in Group 2 called?

Answer 1

Alkaline earth metals

Question 2

Why are the group 2 elements called alkaline earth metals?

Answer 2

Alkaline properties of the metal hydroxides - reactive and don’t occur in their elemental form naturally

Question 3

What are Group 2 elements found in on earth?

Answer 3

Stable compounds

Question 4

What is the most common type of reaction in Group 2 elements?

Answer 4

Redox reactions

Question 5

How many outer-shell electrons does each Group 2 element have?

Answer 5

Two

Question 6

What is the outer-most subshell in Group 2?

Answer 6

Outer s subshell

Question 7

What happens during a redox reaction with Group 2 elements?

Answer 7

Each metal atom is oxidised, losing two electrons to form a 2+ ion with the electron configuration of a noble gas
Another species will gain these two electrons and be reduced

Question 8

What does the Group 2 element become in a redox reaction?

Answer 8

A reducing agent

Question 9

Why does the Group 2 element become a reducing agent?

Answer 9

It has reduced another species

Question 10

What do Group 2 elements form when reacting with oxygen?

Answer 10

A metal oxide

Question 11

What is the general formula of a metal oxide?

Answer 11

MO

Question 12

What ions are in a metal oxide?

Answer 12

M2+ and O2- ions

Question 13

What happens when magnesium reacts with oxygen?

Answer 13

Magnesium burns with a brilliant white light and forms white magnesium oxide

Question 14

What happens to the oxidation number when metals react with oxygen?

Answer 14

They balance

Question 15

What do Group 2 elements form when reacting with water?

Answer 15

An alkaline hydroxide and hydrogen gas

Question 16

What is the general formula of an alkaline hydroxide?

Answer 16

M(OH)2

Question 17

What is the trend in reactivity in Group 2?

Answer 17

Reactivity increases down the group

Question 18

What do Group 2 elements form when reacting with dilute acids?

Answer 18

A salt and hydrogen gas

Question 19

How do Group 2 elements react?

Answer 19

By losing electrons to form 2+ ions

Question 20

What does the formation of 2+ ions from gaseous atoms require?

Answer 20

The input of two ionisation energies

Question 21

What is the trend in ionisation energies down Group 2?

Answer 21

Ionisation energies decrease down the group

Question 22

Why do ionisation energies decrease down Group 2?

Answer 22

The attraction between the nucleus and outer electrons decreases as a result of increasing atomic radius and shielding

Question 23

Why do Group 2 elements become more reactive down the group?

Answer 23

The ionisation energies decrease so it becomes easier to remove an electron from the outer shell

Question 24

What happens when Group 2 oxides react with water?

Answer 24

They release hydroxide ions (OH-) and form alkaline solutions of the metal hydroxide

Question 25

Are Group 2 hydroxides soluble in water?

Answer 25

Only slightly

Question 26

What happens when a Group 2 hydroxide solution becomes saturated?

Answer 26

Any further metal and hydroxide ions will form a solid precipitate

Question 27

What is the trend in solubility of hydroxides down Group 2?

Answer 27

It increases down the group

Question 28

What happens to resulting solutions down the group?

Answer 28

They contain more OH- (aq) ions and are more alkaline

Question 29

Describe the experiment to show the trend in solubility of Group 2 hydroxides

Answer 29

1) Add a spatula of each G2 oxide to water in a test tube 2) Shake. On this scale, there is insufficient water to dissolve all the metal hydroxide that forms. You will have a saturated solution of each metal hydroxide with some white solid undissolved at the bottom of the test tube 3) Measure the pH of each solution - the alkalinity will increase down the group

Question 30

Why are Group 2 compounds used as bases?

Answer 30

Due to their basic properties and ability to neutralise acids

Question 31

Which Group 2 compound is used in agriculture?

Answer 31

Calcium hydroxide, Ca(OH)2

Question 32

Why is calcium hydroxides added to fields?

Answer 32

To increase the pH of acidic soils - the calcium hydroxide neutralises acid in the soil, forming neutral water

Question 33

What two Group 2 compounds are used in medicine?

Answer 33

Calcium carbonate and magnesium hydroxide

Question 34

Why are calcium carbonate and magnesium used in medicine?

Answer 34

They are used as antacids for treating acid indigestion by neutralising hydrochloric acid in the stomach