Group 2

Question 1

What is the trend in group 2 atomic radius and why?

Answer 1

Atomic radius increases because a full energy level of electrons is added between each element

Question 2

What is the trend in group 2 first ionisation energies?

Answer 2

First I.E. decreases because:- All outer electrons in a full s orbital- Shielding increases - Effective nuclear charge on the nucleus decreases- Weaker attraction to outer electrons- Therefore less energy required to remove the outer electron

Question 3

What is the trend in group 2 melting/boiling point?

Answer 3

Melting and boiling points decrease because:- All group 2 elements form 2+ ions in metallic structure- Increased shielding causes weaker effective nuclear charge- Decreases strength of electrostatic attractions with delocalised electrons- Therefore less energy needed to overcome the electrostatic attractions

Question 4

How does reactivity change down group 2?

Answer 4

Reactivity increases ( linked to 1st + 2nd I.E.)

Question 5

What type of reaction is the reaction of a group 2 metal and water?

Answer 5

Redox reactions

Question 6

What is formed when a group 2 metal reacts with 2 water molecules?

Answer 6

A metal hydroxide (base) and hydrogen

Question 7

What temperature water do group 2 metals react with?

Answer 7

Cold water

Question 8

What forms when Mg reacts with water and why?

Answer 8

A white precipitate because the metal hydroxide is not soluble

Question 9

What is formed When Ba reacts with water and why?

Answer 9

No precipitate because the metal hydroxide is soluble

Question 10

What can be said about the reaction of Mg with water?

Answer 10

It is incredibly slow because Mg is the least reactive

Question 11

How can the reaction of Mg and water be sped up?

Answer 11

React Mg with steam to form magnesium oxide and hydrogen

Question 12

What is MgO?

Answer 12

An insoluble base

Question 13

How does solubility change down group 2?

Answer 13

Solubility increases

Question 14

What is barium hydroxide classed as and why?

Answer 14

A strong alkali because it is very soluble

Question 15

What is the trend in solubility for the group 2 hydroxides going down a group?

Answer 15

Solubility increases down group 2

Question 16

What is the trend in solubility for the group 2 sulfates going down a group?

Answer 16

Solubility decreases down group 2

Question 17

What is the trend in solubility for the group 2 carbonates going down a group?

Answer 17

They are all insoluble

Question 18

How can you test if you have a group 2 ion present?

Answer 18

Add sodium carbonate, a white precipitate will form for all group 2 ions as they are all insoluble

Question 19

How can you test for a barium ion in solution?

Answer 19

Add a sulfate ion because a thick white precipitate will form if the barium ion is present because it is insoluble

Question 20

How can you test for a magnesium ion in solution?

Answer 20

Add sodium hydroxide, if a magnesium ion is present a white precipitate will form because it is insoluble

Question 21

What are the two uses of magnesium?

Answer 21

• Mg (l) used in the extraction of titanium from its ore- Magnesium hydroxide used as an antacid

Question 22

What are the two uses of calcium?

Answer 22

• Calcium hydroxide used in agriculture to increase soil pH (neutralise)- Calcium oxide/Calcium carbonate used to remove sulpher dioxide from flue gases

Question 23

What are the two uses of barium?

Answer 23

Barium sulfate used in medicine (barium meal) because it is highly insoluble so outlines the digestive tract for x-ray viewing

Question 24

How is magnesium used to extract titanium from its ore?

Answer 24

2Mg(l) + TiCl4(g) -> Ti(l) + 2MgCl2- 1000 degrees c- Argon atmosphere so neither the Mg or the Ti react with oxygen

Question 25

How is magnesium used as an antacid?

Answer 25

Magnesium hydroxide + 2HCl -> Magnesium chloride + 2H2O

Question 26

How is calcium hydroxide used in agriculture to neutralise soil?

Answer 26

Calcium hydroxide + acid -> Ca(salt) + water

Question 27

Why is it preferable to use CaO to remove sulpher dioxide?

Answer 27

CaO + SO2 produces calcium sulfite only. Whereas calcium carbonate produces calcium sulfite and carbon dioxide