Chemical Tests and Results

Question 1

How do you test for carbonate ions?

Answer 1

Test: Add dilute acid to solution

Result: Solution fizzes and the gas produced turns limewater milky.

Question 2

How do you test for chloride ions?

Answer 2

Test: Add dilute nitric acid, then silver nitrate solution.

Result: White precipitate is formed

Question 3

How do you test for bromide ions?

Answer 3

Test: Add dilute nitric acid, then silver nitrate solution.

Result: Cream precipitate is formed

Question 4

How do you test for iodide ions?

Answer 4

Test: Add dilute nitric acid, then silver nitrate solution.

Result: Yellow precipitate is formed

Question 5

How do you test for nitrate ions?

Answer 5

Test: Heat with aluminium foil and NaOH

Result: Gas turns damp red litmus paper blue

Question 6

How do you test for sulfate ions?

Answer 6

Test: Add dilute nitric acid then barium nitrate solution.

Result: White precipitate is formed.

Question 7

How do you test for sulfite ions?

Answer 7

Test: Add dilute acid then bubble gas through potassium manganate (VII) solution

Result: Gas turns potassium manganate (VII) solution from purple to colourless

Question 8

How do you test for aluminium ions?

Answer 8

Test 1: Add NH3 solution
Result 1: White precipitate, which is insoluble in excess NH3

Test 2: Add NaOH solution
Result 2: White precipitate, which redissolves in excess NaOH to form colourless solution.

Question 9

How do you test for ammonium ions?

Answer 9

Test: Heat with NaOH solution

Result: Gas will turn damp red litmus paper blue

Question 10

How do you test for calcium ions?

Answer 10

Test 1: Add NH3 solution
Result 1: No reaction, or slight white precipitate in excess NH3

Test 2: Add NaOH solution
Result 2: White precipitate, which is insoluble in excess NaOH

Question 11

How do you test for chromium (III) ions?

Answer 11

Test 1: Add NH3 solution
Result 1: Grey-green precipitate which is insoluble in excess NH3

Test 2: Add NaOH solution
Result 2: Green precipitate, which redissolves in excess NaOH to form a green solution

Question 12

How do you test for copper (II) ions?

Answer 12

Test 1: Add NH3 solution
Result 1: Light blue precipitate, which redissolves in excess NH3 to form a dark blue solution

Test 2: Add NaOH solution
Result 2: Light blue precipitate, which is insoluble in excess NaOH

Question 13

How do you test for iron (II) ions?

Answer 13

Test 1: Add NH3 solution
Result 1: Green precipitate, which is insoluble in excess NH3

Test 2: Add NaOH solution
Result 2: Green precipitate which is insoluble in excess NaOH

Question 14

How do you test for iron (III) ions?

Answer 14

Test 1: Add NH3 solution
Result 1: Red-brown precipitate, which is insoluble in excess NH3

Test 2: Add NaOH solution
Result 2: Red-brown precipitate, which is insoluble in excess NaOH

Question 15

How do you test for zinc (II) ions?

Answer 15

Test 1: Add NH3 solution
Result 1: White precipitate, which redissolves in excess NH3 to form a colourless solution

Test 2: Add NaOH solution
Result 2: WHite precipitate which redisssolves in excess NaOH to form a colourless solution

Question 16

Flame test result for lithium ions

Answer 16

Crimson red

Question 17

Flame test result for sodium ions

Answer 17

yellow

Question 18

Flame test results for potassium ions

Answer 18

lilac

Question 19

Flame test results for calcium ions

Answer 19

orange-red

Question 20

Flame test results for barium ions

Answer 20

light green

Question 21

Flame test results for copper (II) ions

Answer 21

blue-green

Question 22

Test for ammonia

Answer 22

Turns damp red litmus paper blue

Question 23

Test for carbon dioxide

Answer 23

Turns limewater milky

Question 24

Test for chlorine

Answer 24

Bleaches damp blue litmus paper

Question 25

Test for hydrogen

Answer 25

Makes a ‘squeaky pop’ with a lighted splint

Question 26

Test for oxygen

Answer 26

Relights a glowing splint

Question 27

Test for sulfur dioxide

Answer 27

Turns potassium manganate (VII) solution form purple to colourless