Chemical Tests

Question 1

Flame test procedure

Answer 1

• Use a nichrome wire
• Dip in hydrochloric acid
• Dip into unknown solid
• Hold in a non-luminous flame

Question 2

Lithium flame test

Answer 2

Red

Question 3

Sodium flame test

Answer 3

Yellow

Question 4

Potassium flame test

Answer 4

Lilac

Question 5

Calcium flame test

Answer 5

Brick red

Question 6

Strontium flame test

Answer 6

Crimson

Question 7

Barium flame test

Answer 7

Apple green

Question 8

Flame test - red

Answer 8

Lithium

Question 9

Flame test - yellow

Answer 9

Sodium

Question 10

Flame test - lilac

Answer 10

Potassium

Question 11

Flame test - brick red

Answer 11

Calcium

Question 12

Flame test - crimson

Answer 12

Strontium

Question 13

Flame test - apple green

Answer 13

Barium

Question 14

Carbonate/hydrogen carbonate test

Answer 14

-Add dilute acid and test gas given off with limewater

→ Effervescence + limewater goes cloudy

Question 15

Sulphate test

Answer 15

-Add dilute HCl
-Add BaCl
→ White precipitate forms

Question 16

Ammonium test

Answer 16

-Warm with NaOH
-Hold damp red litmus above
→ Red litmus goes blue

Question 17

Test for halide ions

Answer 17

• Dissolve substance in water
• Add dilute nitric acid
• Add silver nitrate soloution
• Silver halide forms
• Adding ammonia/putting in UV light has further affects

Question 18

Halide test results for chloride

Answer 18

• White precipitate
• Turns purple-grey in UV light
• Ammonia makes precipitate dissolve

Question 19

Halide test results for bromide

Answer 19

• Cream precipitate
• Turns green-yellow in UV light
• Ammonia makes precipitate dissolve (partially → fully depending on ammonia concentration0

Question 20

Halide test result for iodide

Answer 20

• Yellow precipitate
• No effect from UV light
• No effect from ammonia

Question 21

Ionic equations for carbonate test

Answer 21

Co3(2-) + 2H(+) → H2O + CO2

Question 22

Ionic equations for hydrogen carbonate test

Answer 22

HCo3(-) + H(+) → H2O + CO2

Question 23

Ionic equations for limewater test

Answer 23

Ca(OH)2 + CO2 → CaCO3 + H20

Question 24

Ionic equation for sulphate test

Answer 24

Ba(2+) + SO4(2-) → BaSO4

Question 25

Ionic equation for ammonium test

Answer 25

NH4(+) + OH(-) → H2O + NH3