24 g of Magnesium reacts with 16 g of oxygen. What mass of magnesium oxide will be produced?

• 34 g

• 16 g

• 8 g

• 40 g

Answer explanation

Mass is conserved in chemical reactions - the mass of the products is equal to the mass of the reactants.

What compounds are commonly burned as fuels?

• hydrogencarbonates

• metal oxides

• hydrocarbons

• oxygen

What is limewater used to test for?

• Oxygen

• Water

• Carbon dioxide

• Methane

What is CH₄?

• carbon monoxide

• soot

• water

• methane

The names and formulae of three compounds in the same series are:

Ethane             C₂H₆

Propane           C₃H₈

Butane             C₄H₁₀

The next member in the series is pentane.

What is the formula of pentane?

• C₅H₁₀

• C₅H₁₁

• C₅H₁₂

• C₅H₁₃

What are the products of complete combustion of a hydrocarbon fuel?

• carbon dioxide and water

• oxygen and carbon dioxide

• carbon (soot) and water

• carbon monoxide and water

What is the cause of the smoky flame seen during the incomplete combustion of a hydrocarbon?

• carbon dioxide

• carbon (soot)

• carbon monoxide

• water vapour

What is the test for carbon dioxide?

• turns limewater chalky

• relights a glowing splint

• ignites with a 'pop' sound

• turns cobalt chloride paper pink

What is the test for water?

• turns limewater chalky

• relights a glowing splint

• ignites with a 'pop' sound

• turns cobalt chloride paper pink

What toxic gas is produced during the incomplete combustion of hydrocarbons?

• carbon

• carbon dioxide

• carbon monoxide

• water vapour