Atmosphere and environment - Air Part 1

A 100 cm³ sample of bottled gas used for diving was placed in a gas syringe in the apparatus shown.

What is the percentage of oxygen in the bottled gas?

• 20%

• 30%

• 70%

• 80%

Which noble gas is present in the largest percentage by volume in air?

• argon

• helium

• krypton

• neon

Which list contains only gases that are always present in unpolluted air?

• oxygen, nitrogen, carbon dioxide, argon, carbon monoxide, nitrogen dioxide

• oxygen, nitrogen, carbon dioxide, argon, neon

• oxygen, nitrogen, carbon dioxide, nitrogen dioxide, ozone

• oxygen, nitrogen, carbon monoxide, methane, sulfur dioxide

Which gas is not obtained industrially by fractional distillation?

• ammonia

• argon

• nitrogen

• oxygen

The diagram shows steel wool inside a test-tube. The test-tube is inverted in water, trapping air inside.What will be the water level inside the tube after several days?

• A

• B

• C

• D

A gas G

(1) has no smell,

(2) is not poisonous,

(3) reacts with hydrogen at high temperature and pressure.

What is gas G?

• carbon monoxide

• helium

• nitrogen

• chlorine

Dry air is a mixture of gases of which 99% is nitrogen and oxygen.

What is the main constituent of the remaining 1%?

• argon

• helium

• hydrogen

• water vapour

A solid substance Z burns in air to form a product that is gaseous at 20 °C.

What is Z?

• hydrogen   

• carbon monoxide

• carbon

• magnesium

The apparatus shown was set up with 100 cm³ volume of air in the tube.

The volume of gas in the tube was measured at intervals for six days.

• A

• B

• C

• D

The diagram shows an experiment to determine the percentage of oxygen in air.

• A

• B

• C

• D