Topic 6

Question 1

What are group 1 metals also referred to as?

Answer 1

Alkali metals

Question 2

Why do alkali metals have similar chemical properties?

Answer 2

Because they all have one outer electron

Question 3

Do alkai metals form ionic compounds or covalent bonds?

Answer 3

They form ionic compounds

Question 4

Name 2 physical properties of Group 1 metals?

Answer 4

1. lower melting and boiling points

2. Very soft - can be cut with a knife

Question 5

Why are group 1 metals very reactive

Answer 5

Because it is easy for them to lose an electron to gain a full outer shell

Question 6

Why are group 1 metals more reactive further down the group?

Answer 6

The electrons are further away from the nucleus which means it can lose its outer electron more easily as the electron would be less attracted to the nucleus

Question 7

What happens when alkali metals are put in water?

Answer 7

They react vigorously and a hydroxide and hydrogen gas is produced

Question 8

Predict what would happen if you reacted lithium with water?

Answer 8

The lithium would move around the surface, fizzing furiously

Question 9

Predict what would happen if you react Sodium and Potassium with water

Answer 9

They would do the same as lithium but they would also melt in the heat of the reaction. Potassium gets hot enough to ignite the hydrogen gas being produced.

Question 10

Predict what would happen if you react caesium and rubidium with water?

Answer 10

They would cause a huge explosion

Question 11

What are group 7 elements also known as?

Answer 11

Halogens

Question 12

Why do group 7 elements have similar chemical properties?

Answer 12

They all have 7 electrons in their outer shell

Question 13

What do halogens exist as? (type of molecule?)

Answer 13

They exist as diatomic molecules. They share a pair of electrons ina covalent bond so both atoms can gain a full outer shell. (e.g Cl2)

Question 14

What happens to the melting and boiling points of the halogens as you go down the group?

Answer 14

They increase

Question 15

What is Chlorine like in room temp?

Answer 15

1. fairly reactive
2. Poisonous
3. Green gas

Question 16

What is Bromine like as a liquid?

Answer 16

2. Poisonous

2. red-brownish

Question 17

What is Bromine like at room temp?

Answer 17

Gives off an orange vapour at room temp

Question 18

What is iodine like as a solid?

Answer 18

dark grey crystalline solid

Question 19

What is iodine like as a gas?

Answer 19

gives off purple vapour when heated

Question 20

Predict what astatine would be like at room temp?

Answer 20

A black solid with a melting point of around 300

Question 21

How do you test for chlorine?

Answer 21

By holding a piece of damp blue litmus paper over a gas, and if there is chlorine present, the paper would turn white.

Question 22

Why may the litmus paper turn red for a moment when testing for chlorine?

Answer 22

This is because a solution of chlorine is acidic

Question 23

What is the trend in reactivity as you go down group 7?

Answer 23

Reactivity decreases

Question 24

Why does reactivity decrease as you go down a group?

Answer 24

1. A halogen atom needs to gain one electron to get a full outer shell
2. The easier it is to gain the electron, the more reactive the element would be
3. As you move further away from the nucleus, it gets harder to attract the extra electron. This means halogens would be less reactive as you go down the group

Question 25

What can halogens and metals react to make?

Answer 25

Metal halides e.g. sodium and chloride make NACL

Question 26

What can hydrogen and halogens react to form?

Answer 26

Hydrogen halides e.g. hydrogen and chlorine to make hydrogen chloride

Question 27

What are some properties of hydrogen halides?

Answer 27

1. They're soluble | 2. They can dissolve in water to form acidic solutions e.g. HCl in water

Question 28

Would halogens have similar or different properties and what would this mean about halogens further down in the group?

Answer 28

They have similar properties, meaning we can predict the properties of astatine and fluorine

Question 29

What would happen in a displacement reaction between a halogen and halide ions?

Answer 29

The more reactive element displaces the less reactive element and the halide ions may be oxidised (lose electrons) whilst the halogens may be reduced (gain electrons)

Question 30

Describe how you would carry out a halogen displacement reaction?

Answer 30

1. Measure amount of halide salt solution in a test tube 2. Add a few drops of a halogen solution to it and shake gently 3. If there is a colour change, a reaction has happened and the halogen has displaced the halide ion. If no reaction happens, there wont be a colour change and the halogen is less reactive than the halide and so cant replace it 4. Use different combinations of hydrogen and halide ions

Question 31

What would you expect to see if you mixed potassium chloride with chlorine water? (both colourless and aqueous)

Answer 31

No reaction

Question 32

What would you expect to see if you mixed potassium bromide with chlorine water?

Answer 32

An orange solution formed. (bromine) as the bromide ions are oxidised to bromine

Question 33

What would you expect to see if you mixed chlorine water with potassium iodide?

Answer 33

A brown solution formed as the iodide ions are oxidised to Iodine

Question 34

What would you expect to see if you mixed bromine water with Potassium iodide?

Answer 34

A brown solution formed as the iodide ions are oxidised to iodine

Question 35

What would you expect to see if you mixed Potassium bromide with iodine water?

Answer 35

No reaction

Question 36

Judging by group 7's reactivity, how would you think Astatine would react?

Answer 36

It wont react as it cant displace any other element

Question 37

What are group 0 elements also known as?

Answer 37

Noble gases

Question 38

What are some properties of Noble gases?

Answer 38

1. They are inert 2. Colourless 3. Non flammable as they're inert

Question 39

What colour gases are group 0 at room temperature?

Answer 39

They are colourless at room temperature

Question 40

Why are noble gases inert

Answer 40

Because they already have a full outer shell

Question 41

Are noble gases monotonic or diatomic?

Answer 41

They are monatomic (single atoms)

Question 42

How does argon protect filament lamps?

Answer 42

As its non-flammablem it stops the very hot filament from burning up

Question 43

How does argon, krypton, and xenon help in flash photography

Answer 43

It stops the flash filament from burning up during the high temperature flashes

Question 44

How are argon and helium used to protect metals

Answer 44

They protect metals that are being welded as the inert atmosphere stops the hot metal reacting with oxygen

Question 45

How is Helium used in airships and balloons?

Answer 45

It has a lower density than air, so it makes balloons float. It is also non-flammable which makes it safer to use than hydrogen

Question 46

What is the trend in boiling/melting point and density as you move down the group?

Answer 46

It increases as you move down the group