exam

Question 1

Properties of the halogens

Answer 1

1. low solubulity in water

2. Disoolve easily in organic compounds like hexane

Question 2

Colour and state at room temperature of fluorine

Answer 2

pale yellow gas

Question 3

Colour and state at room temperature of chlorine

Answer 3

green gas

Question 4

Colour and state at room temperature of bromine

Answer 4

red-brown liquid

Question 5

Colour and state at room temperature of iodine

Answer 5

grey solid

Question 6

Colour in water for chlorine

Answer 6

colourless

Question 7

Colour in water for bromine

Answer 7

yellow/orange

Question 8

Colour in water for iodine

Answer 8

brown

Question 9

Colour in hexane for chlorine

Answer 9

colourless

Question 10

Colour in hexane for bromine

Answer 10

orange red layer

Question 11

Colour in hexane for iodine

Answer 11

pink violet

Question 12

Trend in reactivity as you go down the groups of halgens

Answer 12

1. Get less reactive down the group
2. As you go down the group the atom becomes karger so the outer electrns are further away from the nucleus and they are shielded more fro the possitive attraction of the nucleus due to the inner elecectons
3. tHis makes it harder for larger atoms to attract the elctron needed to form an ion

Question 13

Trend in boiling and melting points as you go down the group halogens

Answer 13

1. As you go down group 7 there is an increase in electron shells and electrons meaning that the london forces between the halogen moleucles get stronger
2. The increase in london forces meansmore energy is required to break these intermoleuclar forces so the melting and boiling points increases

Question 14

What happens to the thing that is displaced

Answer 14

oxidised

Question 15

WHta happens to the thing that is doing the displacing

Answer 15

Reduced

Question 16

Reaction between halogen and group 1 and 2 metals

Answer 16

They produce halide salts

Question 17

WHta is a disproportionation reaction

Answer 17

When a substance is simuktaneously oxidised and reduced

Question 18

Reaction between halogen and cold alkali

Answer 18

1, Disproportionation reaction

x2 + 2NaOH >NaOx + NaX + H20

ionic= x2 + 2OH- > OX- + X- + H20

Question 19

Reaction between halogen and hot alkali

Answer 19

1, Disproportionation reaction

3x2 + 6NaOH >NaxO3 + 5NaX + 3H20

ionic= 3x2 + 6OH- > XO3- + 5X- +3 H20

Question 20

Reaction between chlorine and sodium hydroxide

Answer 20

1. Makes bleach (NaCLO)

2. 2NaOH +CL2 > NaCLO + NaCL + H2O

Question 21

Reaction between chlorine and water ( 2 equations

Answer 21

1. Disproportionation reaction

You get hydrochloric acid and hypochlorous acid

CL2 + H20 > HCL + HCLO

This is a reversible reaction

HCLO + H20 > CLO- + H3O+

Question 22

Test for halogens

Answer 22

1. Add dilute nitric acid
2. Add silver nitrate solution
3. A precipitate wil be formed of the silver halid3

Question 23

Colour of silver precipitate of fluoride

Answer 23

no precipitate AgF is soluble

Question 24

Colour of silver precipitate of chloride

Answer 24

White precipitate

Question 25

Colour of silver precipitate of bromide

Answer 25

Cream precipitate

Question 26

Colour of silver precipitate of iodide

Answer 26

yellow precipitate

Question 27

AgCl when you add ammonia solution

Answer 27

precipitate dissolves in dilute ammonai solution to give a colourless solution

Question 28

AgBr when you add ammonia solution

Answer 28

Precipitate remains unchanged if dilute amminia solution is added but will dissolve in concentarted ammonia solution to give a colourless solution

Question 29

AgI when you add ammonia solution

Answer 29

Precipitate does not dissolve even in concentrated ammonia solution

Question 30

What is the tests for sulfates

Answer 30

1. Add dilute HCL followed by barium chloride solution

2. If a white precipitate of barium sulfate forms the compound contained sulfate

Question 31

Wgat is the test for ammonium compounds

Answer 31

1. Ammonia is alkaline so we use red litmus paper
2. A dd sodium hydroxide to mystery substance
3. Gently heat the mixture
4. If damp red litmus paper turns blue ammonia present