Positive ions and gas tests

What is initially observed when sodium hydroxide is added in excess to a solution of Fe²⁺ ions?

• Green precipitate

• Brown precipitate

• Blue precipitate

• White precipitate

This test tube may contain Hydrogen. How could we test for this?

• Insert a glowing splint

• Insert a lit splint

• Insert a delivery tube

• Use litmus paper

What is lime water an aqueous solution of?

• Calcium hydroxide

• Calcium carbonate

• Calcium chloride

• Hydrogen peroxide

What colour does litmus paper turn in the presence of chlorine?

• Red

• Blue

• White

• Yellow

How does carbon dioxide react with a lit splint?

• Squeaky pop

• It explodes

• Increases flame

• Extinguish flame

How do you test for oxygen?

• Use a lit splint

• Use a glowing splint

• Use litmus paper

• Use a delivery tube

Complete the equation:

Acid + Metal ---> __________ + Hydrogen

• Water

• Salt

• Acid

• Alkali

A green precipitate formed when sodium hydroxide is added to an unknown solution indicates the presence of.....

• Iron(III)

• Calcium

• Copper

• Iron(II)

Dilute sodium hydroxide can be added to an unknown solution to indicate the presence of....

• Iron(II)

• Iron(III)

• Copper

• All of them

Which metal produces a brick red flame?

• Barium

• Calcium

• Silver

• Lead