Testing Stuff

Question 1

How do you conduct a flame test?

Answer 1

Dip a wire loop (or soaked wooden splint) into the substance and hold it into a bunsen flame

Question 2

What colour flame does lithium produce?

Answer 2

Red

Question 3

What colour flame does sodium produce?

Answer 3

Yellow

Question 4

What colour flame does potassium produce?

Answer 4

Lilac

Question 5

What colour flame does calcium produce?

Answer 5

Brick red

Question 6

What colour flame does barium produce?

Answer 6

Apple green

Question 7

What happens in sodium hydroxide tests?

Answer 7

When we react sodium hydroxide with a salt, an insoluble metal hydroxide forms as a precipitate.
By identifying the metal hydroxide, this lets us see what metal was in the salt.

Question 8

What colour is the precipitate when copper (II) is reacted with sodium hydroxide?

Answer 8

Light blue

Question 9

What colour is the precipitate when iron (II) is reacted with sodium hydroxide?

Answer 9

Light green

Question 10

What colour is the precipitate when iron (III) is reacted with sodium hydroxide?

Answer 10

Reddish brown

Question 11

How do you test for carbonates?

Answer 11

Add dilute HCL - produces gas

Bubble gas through limewater - should turn milky (shows it is CO2)

Question 12

How do you test for ammonia?

Answer 12

Ammonia is an ALKALINE gas so it turns damp red litmus paper blue

Question 13

How do you test for ammonium salts?

Answer 13

Add sodium hydroxide solution - ammonium salts give off ammonia

Question 14

How do you test for sulphates?

Answer 14

Add barium chloride solution - White precipitate formed

Question 15

What are halides?

Answer 15

Ions of group 7 elements
e.g.
Chloride
Bromide
Iodide

Question 16

How do you test for halides?

Answer 16

Add silver nitrate solution

Question 17

What is produced when chloride ions react with silver nitrate?

Answer 17

White precipitate

Question 18

What is produced when bromide ions react with silver nitrate?

Answer 18

Cream precipitate

Question 19

What is produced when iodide ions react with silver nitrate?

Answer 19

Yellow precipitate

Question 20

How do you test for oxygen?

Answer 20

Relights a glowing splint

Question 21

How do you test for hydrogen?

Answer 21

Produces a squeaky pop sound when held by lit splint

Question 22

How do you test for carbon dioxide?

Answer 22

Bubble through limewater - turns milky

Question 23

How do you test for chlorine gas?

Answer 23

Will bleach damp blue litmus paper

Question 24

How do you test for alkenes?

Answer 24

Shake with bromine water - alkenes only show colour change from brown/orange to colourless

Question 25

How do you test for alcohols?

Answer 25

Heat with acidified potassium dichromate solution - alcohols give colour change from ORANGE to GREEN

Question 26

How does sodium react with water?

Answer 26

It fizzes rapidly, moves around and melts to form a ball on the surface of the water

Question 27

How does lithium react with water?

Answer 27

Fizzes steadily and floats, becoming smaller until it eventually disappears

Question 28

Which metals react with water and what do they produce?

Answer 28

Potassium Sodium Lithium Form metal hydroxides and hydrogen gas

Question 29

How does potassium react with water?

Answer 29

Sparks Lilac flame Very quick reaction