iGCSE chemistry Edexcel chemical tests

What happens when you add sodium hydroxide to a solution containing NH₄⁺ions?

ammonia gas forms

How do you test for ammonia gas

damp red litmus paper turns blue

What is the test for carbonate ions?

Effervescence when you add acid, bubble the gas through limewater which goes cloudy

What is the test for carbon dioxide?

Bubble gas through limewater which goes cloudy

What is the test for sulfate ions?

White precipitate forms when Barium nitrate is added.

What is the test for a halide ion?

Add nitric acid followed by silver nitrate

What to you see when nitric acid followed by silver nitrate is added to chloride ions?

white precipitate forms

What to you see when nitric acid followed by silver nitrate is added to bromide ions?

cream precipitate forms

What to you see when nitric acid followed by silver nitrate is added to iodide ions?

yellow precipitate forms

Name the precipitate when nitric acid followed by silver nitrate is added to sodium chloride

silver chloride

Give the formula for the precipitate when nitric acid followed by silver nitrate is added to potassium bromide

AgBr

What is the wire made of that is used for flame tests?

Nichrome

What do you clean the nichrome wire in before a flame test?

hydrochloric acid

What colour is the flame in the presence of calcium ions?

orange -red

What colour is the flame in the presence of lithium ions?

red

What colour is the flame in the presence of sodium ions?

yellow

What colour is the flame in the presence of potassium ions?

lilac

What colour is the flame in the presence of copper ions?

blue-green

What do you observe when you add sodium hydroxide to iron (II) ions?

green precipitate forms

What do you observe when you add sodium hydroxide to iron (III) ions?

orange brown precipitate

What do you observe when you add sodium hydroxide to copper (II) ions?

blue precipitate forms

What is the formula of the green precipitate formed when sodium hydroxide is added to a solution.

Fe(OH)₂

What is the formula of the orange-brown precipitate formed when sodium hydroxide is added to a solution.

Fe(OH)₃

What is the formula of the blue precipitate formed when sodium hydroxide is added to a solution.

Cu(OH)₂

If you get a blue precipitate when sodium hydroxide is added which ions are present?

Cu²⁺

If you get a green precipitate when sodium hydroxide is added which ions are present?

Fe²⁺

If you get a orange-brown precipitate when sodium hydroxide is added which ions are present?

Fe³⁺

What is present if you get a lilac flame?

K⁺ ions

What is present if you get a red-orange flame?

Ca²⁺ ions

What is present if you get a yellow flame?

Na⁺ ions

What is present if you get a red flame?

Li⁺

What is the name of the precipitate formed when Barium chloride is added to a solution containing sulfate ions?

barium sulfate

What gas is produced when a carbonate reacts with acid?

carbon dioxide

What is the test for oxygen gas?

glowing splint relights

What is the test for hydrogen gas?

lighted splint makes squeaky pop

What is the test for chlorine gas?

damp blue litmus turns red then white

What gas is present when damp red litmus turns blue?

Ammonia

What gas is present when damp blue litmus turns red then white?

Chlorine

What is the test for water?

anhydrous copper sulfate

What is the colour change when anhydrous copper sulfate come in contact with water?

white solid to blue solid

How do you test if water is pure?

Measure the boiling point.

What is the boiling point of water?

100°C