Air

What is the approximate volume of composition of gases present in dry air?

• 78% nitrogen,

  1% oxygen,

  21% other gases (largely argon and 0.04% carbon dioxide)

• 78% nitrogen,

  21% oxygen,

  1% other gases (largely argon and 0.04% carbon dioxide)

• 78% oxygen,

  21% nitrogen,

  1% other gases (largely argon and 0.04% carbon dioxide)

What are the gases in parts 1, 2 and 3?

• 1 - oxygen

  2 - nitrogen

  3 - carbon dioxide and noble gases

• 1 - nitrogen

  2 - oxygen

  3 - carbon dioxide and noble gases

• 1 - carbon dioxide and noble gases

  2 - nitrogen

  3 - oxygen

• 1 - carbon dioxide and noble gases

  2 - oxygen

  3 - nitogen

What is the approximate volume of oxygen in 50 cm³ of air?

• 5 cm³

• 10 cm³

• 20 cm³

• 40 cm³

An 80 cm³ sample of air is trapped in a syringe. The air is slowly passed over heated iron in a tube until there is no further decrease in volume.

What is the volume of gas remaining?

• 16 cm³

• 20 cm³

• 64 cm³

• 80 cm³

Which diagram best represents a mixture of nitrogen and oxygen?

• 
• 
• 

Select the uses of oxygen.

• Making of steel

• In oxygen tanks

• Photosynthesis

• In light bulbs

What are the sources of carbon monoxide?

• Incomplete combustion of carbon-based fuels

• Complete combustion of carbon-based fuels

• Forest fires

• Lightning activity

Which of the following air pollutants result in acid rain?

• carbon monoxide

• carbon dioxide

• nitrogen monoxide

• nitrogen dioxide

• sulfur dioxide

Select the pollutants that cause corrosion of limestone buildings and metallic structures.

• carbon monoxide

• sulfur dioxide

• nitrogen dioxide

• methane

Which of the following explains how acid rain is formed?

• Carbon monoxide (CO) reacts with oxygen and water vapour and dissolve in rainwater.

• NO and NO₂ react with unburnt hydrocarbons.

• SO₂ and oxides of nitrogen react with oxygen and water vapour and dissolve in rainwater.