Identifying Ions Required Practical 7

Question 1

Lithium flame test

Answer 1

Crimson flame

Question 2

Sodium flame test

Answer 2

Yellow flame

Question 3

Potassium flame test

Answer 3

Lilac flame

Question 4

Calcium flame test

Answer 4

Orange-red flame

Question 5

Copper flame test

Answer 5

Green flame

Question 6

Metal hydroxide ppte
White precipitates

Answer 6

Calcium
Magnesium
Aluminium-> excess Aluminium ppte redissolves

Question 7

Metal hydroxide ppte
Blue precipitate

Answer 7

Copper 2 ions

Question 8

Metal hydroxide ppte
Green precipitates

Answer 8

Iron 2 ions

Question 9

Metal hydroxide ppte
Brown precipitates

Answer 9

Iron 3 ions

Question 10

Test for carbon dioxide (carbonate)

Answer 10

Bubble gas through lime water
Positive result: lime water goes cloudy

Question 11

Test for halide ions

Answer 11

Add nitric acid and silver nitrate
Chloride ions-> white ppte
Bromide ions-> cream ppte
Iodide ions-> yellow ppte

Question 12

Test for sulfate ions

Answer 12

Add hydrochloric acid and barium chloride
Positive result: white ppte

Question 13

Test for hydrogen (hydroxide)

Answer 13

Squeaky pop test
Buring splint held at the open of a test tube
Positive test: pop

Question 14

Test for oxygen (oxide)

Answer 14

Use a glowing splint inserted into a test tube
Positive result: splint relights

Question 15

Test for chlorine (chloride)

Answer 15

Damp blue litmus paper and put it in gas
Positive result: blue litmus paper is bleached and turns white