Analysis

Question 1

Chemical test for water

Answer 1

Add unknown liquid to anhydrous copper ll sulfate if it turns blue water is present

Question 2

Physical test for water

Answer 2

Boil substance and measure boiling point if its 100^c it is pure water

Question 3

Colour produced from copper sulfate

Answer 3

Blue-green

Question 4

Colour produced from lithium nitrate

Answer 4

Red

Question 5

Colour produced from calcium nitrate

Answer 5

Orange-red

Question 6

Colour produced from Potassium hydroxide

Answer 6

Lilac

Question 7

Colour produced from sodium sulfate

Answer 7

Yellow

Question 8

Test for oxygen

Answer 8

Introduce a glowing splint to unknown gas if splint relights O2 is present

Question 9

Test for carbon dioxide

Answer 9

Bubble unknown gas through lime water if it turns cloudy carbon dioxide is present

Question 10

Test for hydrogen

Answer 10

Introduce a it sprint to unknown gas if a squeaky pop is head Hz is present

Question 11

Test for ammonia

Answer 11

Add damp red litmus paper to unknown gas if it turns blue ammonia is present

Question 12

Test for chlorine

Answer 12

Add damp blue litmus paper to unknown gas it it turns red then bleaches white chlorine is present

Question 13

Pros of nichrome wire loop

Answer 13

Clean flame with colour only arising from the substance on the loop

Question 14

Cons of nichrome loop

Answer 14

Loop has to be absolutely clean and dried so there is no contamination from previous samples

Question 15

pros of soaked splint

Answer 15

No risk of contamination from other samples

Question 16

Cons of soaked splints

Answer 16

Splint burns so con obscure flame colder

Question 17

Why is roaring blue flame used and not safety flame

Answer 17

Blue has a higher heat so colour is more visible

Question 18

How to test for carbonate ions (co3^2-)

Answer 18

Add solution containing carbonate ions to dilute acid (HCL, nitric) in a test tube and effervescence should occur

Question 19

How to test for cations

Answer 19

Add solution containing cation to sodium hydroxide and record observations + precipitates formed

Question 20

Observations of iron II sulfate and NaOH

Answer 20

Green precipitate formed

Question 21

Observations wen NaOH is added to ammonium chloride

Answer 21

No visible change so use red litmus paper if it turns blue NH3 gas confirmed

Question 22

Observations when NaOH is added to copper ll sulfate

Answer 22

light blue turns to a bright blue precipitate

Question 23

Observations when Na OH is added to iron (iii) nitrate

Answer 23

Pale yellow solution turns to a dark orange precipitate

Question 24

How to test for chloride, bromide, iodide ions

Answer 24

Add solution containing halide ions and add nitric acid then add silver nitrate

Question 25

Observations of testing for chloride ions

Answer 25

white precipitate formed

Question 26

Observations of testing for bromide ions

Answer 26

Cream precipitate formed

Question 27

Observations for test for iodide ions

Answer 27

yellow precipitate formed

Question 28

How to test for sulfate ions

Answer 28

Add solution containing sulfate ions to a test tube containing HCL and barium chloride and record results

Question 29

Observations of testing sulfate ions

Answer 29

Turns cloudy, effervescence, white precipitate formed