Tests

Question 1

Test for double bond

Answer 1

Few drops of bromine water ( redish brown colour )

If it has a double bond it goes colourless

Question 2

Tollens test

Silver mirror

Answer 2

Solution of silver nitrate in aqueous ammonia
Silver mirror formed if its an aldehyde

[ Ag(NH3)2]+ + e- ➡️ Ag + 2NH3

Question 3

Fehlings test

Answer 3

Blue copper (ll) ions to a red precipitate copper (i) ion

Oxides aldehydes

Cu 2+ + e- ➡️ Cu+

Question 4

Halogenalkane

R-X

Answer 4

Add NaOH and warm
Acidify with HNO3
Add AgNO3

Precipitate of AgX

Question 5

Alcohol

R-OH

Answer 5

Acidified K2Cr2O7

Orange to green colour

Primary alcohols
Secondary alcohols
Aldehydes

Question 6

Carboxylic acid

Answer 6

Add NaHCO3

Carbon dioxide given off

Question 7

Barium chloride and NaOH

Answer 7

Initial = colourless solution
NaOH = colourless solution
Excess NaOH = colourless solution

Question 8

Calcium bromide and NaOH

Answer 8

Initial = colourless solution
NaOH = slight white ppt
Excess NaOH = slight white ppt

Question 9

Magnesium chloride and NaOH

Answer 9

Initial = colourless solution
NaOH = slight white ppt
Excess NaOH = white ppt

Question 10

Strontium chloride and NaOH

Answer 10

Initial = colourless solution
NaOH = slight white ppt
Excess NaOH = slight white ppt

Question 11

Barium chloride and H2SO4

Answer 11

Initial = colourless solution
H2SO4 = white ppt
Excess H2SO4 = white ppt

Question 12

Calcium bromide and H2SO4

Answer 12

Initial = colourless solution
H2SO4 = slight white ppt
Excess H2SO4= slight white ppt

Question 13

Magnesium chloride and H2SO4

Answer 13

Initial = colourless solution
H2SO4 = slight white precipitate
Excess H2SO4 = colourless solution

Question 14

Strontium chloride and H2SO4

Answer 14

Initial = colourless solution
H2SO4 = white ppt
Excess H2SO4 = white ppt

Question 15

Ammonium chloride and sodium hydroxide

Answer 15

Damp red litmus paper = blue

Question 16

Sodium hydroxide

Answer 16

Damp red litmus paper = blue

Question 17

Ammonia solution

Answer 17

Damp red litmus paper = blue

Question 18

Limewater

Answer 18

Colourless solution to cloudly

Question 19

Test of sulphate ions

Answer 19

White precipitate forms

Question 20

Potassium chloride and HNO3

Answer 20

White precipitate

Question 21

Potassium bromide and HNO3

Answer 21

Cream ppt

Question 22

Potassium iodide and HNO3

Answer 22

Yellow precipitate

Question 23

Potassium chloride and NH3

Answer 23

Colourless solution

Question 24

Potassium bromide and NH3

Answer 24

Cream precipitate

Question 25

Potassium iodide and NH3

Answer 25

Yellow precipitate

Question 26

Potassium chorine and con NH3

Answer 26

Colourless solution

Question 27

Potassium bromide and con NH3

Answer 27

Colourless solution

Question 28

Potassium iodide and con NH3

Answer 28

Yellow preciptate

Question 29

Potassium chloride and concentrated sulphuric acid | And paper test

Answer 29

Effervescence Red

Question 30

Potassium bromide and con sulphuric acid

Answer 30

Effervescence Brown gas produced Solution turns deep brown / red

Question 31

Potassium iodide and con sulphuric acid And paper test

Answer 31

Solution goes red/brown Immediately Brown gas produced Turns black/grey