GCSE Chemistry Chemical tests

Which of the following is a chemical test for oxygen gas?

• relights a glowing splint

• bleaches damp litmus paper white

• pops with a lit splint

• turns limewater cloudy

Which of the following is a chemical test for hydrogen gas?

• relights a glowing splint

• turns limewater cloudy

• bleaches damp litmus paper white

• burns with a pop when lit splint is used

A gas turns damp red litmus paper blue. The gas is ....

• sulfur dioxide

• oxygen

• ammonia

• carbon dioxide

What term is given to a solid formed in a reaction between two solutions?

• Filtrate

• Precipitate

• Residue

• Solution

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

• Iron (II)

• Iron (III)

• Copper (II)

• All of them

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

• Green precipitate

• Brown precipitate

• Blue precipitate

• White precipitate

In flame testing, what element gives a yellow flame

• Carbon

• Sodium

• Copper

• Lithium

When doing a flame test, what element gives a purple/lilac flame?

• Barium

• Calcium

• Potassium

• Copper

Chlorine gas.......

• will turn limewater chalky

• will turn damp blue litmus paper red then bleach it white

• will burn with a pop

• will turn damp red litmus blue paper

A positive test for the presence of water shows what colour change for anhydrous copper sulphate

• white to blue

• blue to white

• pink to blue

• blue to pink