Chemical Analysis Paper 2 (Tests)

Question 1

Test and result for chlorine gas

(gas test)

Answer 1

Test: Damp blue litmus paper
Result: Bleaches it white

Question 2

Test and result for carbon dioxide gas

(gas test)

Answer 2

Test: Bubble through limewater
Result: Turns it cloudy

Question 3

Test and result for oxygen gas

(gas test)

Answer 3

Test: Glowing splint
Result: Relights it

Question 4

Test and result for hydrogen gas

(gas test)

Answer 4

Test: Lit splint
Result: Squeaky pop

Question 5

Test and result for carbonate ions

(anion test)

Answer 5

Test: React with an acid, bubble gas through limewater
Result: Turns it cloudy

Question 6

Test and result for sulfate ions

(anion test)

Answer 6

Test: Remove impurities with hydrochloric acid, add barium chloride
Result: Forms a white precipitate

Question 7

Test for halide ions

(anion test)

Answer 7

Test: Remove impurities with nitric acid, add silver nitrate

Question 8

Result for chloride ions

(halide test)

Answer 8

Result: White precipitate

Question 9

Result for bromide ions

(halide test)

Answer 9

Result: Cream precipitate

Question 10

Result for iodide ions

(halide test)

Answer 10

Result: Yellow precipitate

Question 11

2 tests for metal ions

(cation test)

Answer 11

1. Test: Flame test
2. Test: Sodium hydroxide test

Question 12

Result for lithium ions

(flame test)

Answer 12

Result: Crimson flame

Question 13

Result for calcium ions

(flame test)

Answer 13

Result: Orange/red flame

Question 14

Result for potassium ions

(flame test)

Answer 14

Result: Lilac flame

Question 15

Result for copper(II) ions

(flame test)

Answer 15

Result: Green flame

Question 16

Result for sodium ions

(flame test)

Answer 16

Result: Yellow flame

Question 17

Result for magnesium ions

(sodium hydroxide test)

Answer 17

Result: White precipitate

Question 18

Result for calcium ions

(sodium hydroxide test)

Answer 18

Result: White precipitate

Question 19

Result for aluminium ions

(sodium hydroxide test)

Answer 19

Result: White precipitate, if sodium hydroxide added in excess then colourless solution

Question 20

Result for iron(II) ions

(sodium hydroxide test)

Answer 20

Result: Green precipitate

Question 21

Result for iron(III) ions

(sodium hydroxide test)

Answer 21

Result: Brown precipitate

Question 22

Result for copper(II) ions

(sodium hydroxide test)

Answer 22

Result: Blue precipitate

Question 23

What is an instrumental method? Why?

Answer 23

• tests carried out using scientific equipment e.g. Flame emission spectroscopy
• sensitive, fast and accurate unlike chemical tests

Question 24

Flame emission spectroscopy? How?

Answer 24

• sample is placed in a flame
• light given off is passed through a spectroscope
• line spectrum is outputted
• metal ion identified along with its concentration

Question 25

Advantages to Flame emission spectroscopy?

Answer 25

Can be used on very small substance
Accurate, sensitive and fast

Question 26

Disadvantages to Flame emission spectroscopy?

Answer 26

• Specialist staff
• Expensive equipment

Question 27

Difference in mobile and stationary phase?

(chromatography)

Answer 27

• Mobile phase is the solvent, which the solute can move through
• Stationary phase is the paper, which the solute cannot move through