O Level Chemistry & IP Chemistry Notes by 10 Year Series Author - Chemistry Specialist

O Level Chemistry Made Easy

Air Pollutants

O Level Chemistry: Air and The Atmosphere

Air or some like to call it Atmosphere is considered a ‘minor’ chapter in GCE O Levels Chemistry examination, so much so that many teachers do not emphasise on their existence, not to mention importance.

As described by my Sec 4 Chemistry students, many of their Chemistry School teachers:

  1. Ask the students to read textbook on their own
  2. Give them 1 page summary mindmap or worksheet and ask them to just memorise it
  3. Never even mention that Air is part of examination

Now, i beg to differ on this. If you are an educator (teacher, HOD or tutor) or even a parent that follows closely with Ten Years Series, you would realised that questions on Air have been appearing in recent year’s GCE O Levels Chemistry Examination.

Many a times, they appear in Section A (Short Questions) of Paper 2, and commonly in the form of Tables, Charts (Pie or Bar) or even Graphs. They are Application-Based questions and require the student to apply their concepts, rather than simply regurgitate what they memorise. TAKE NOTE especially if you are aiming to ACE your Chemistry!

Students must know the essential concepts of this topic well in order to be able to understand and comprehend these application fast, and solve them in limited time in examination conditions.

Let’s check out some questions on Air (Atmosphere):

Question 1:

Unpolluted rain water has a pH of about 6. Which of the following gas causes this pH?

A. Carbon Dioxide

B. Oxygen

C. Nitrogen Dioxide

D. Sulfur Dioxide

&

Question 2:

Which gas is NOT produced when hydrocarbons are burnt in the internal combustion engines?

A. Carbon dioxide

B. Carbon monoxide

C. Hydrogen

D. Oxide of nitrogen

&

Question 3:

Powdered calcium carbonate is commonly placed near the chimneys in coal-burning power station, in order to reduce atmospheric pollution by removing the waste gases. Which waste gas will not be removed by the powdered calcium carbonate?

A. Sulfur trioxide, SO3

B. Nitrogen dioxide, NO2

C. Carbon monoxide, CO

D. Phosphorous (V) oxide, P2O5

Now is your time to do some work. Try out the questions and see how much you know about this topic.

PS: Leave your answers and any suggested solutions in the “Leave a Reply” section below.