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2007 - Q12

 

Which of the following is always produced during combustion of fossil fuels?

 

(A) Water

(B) Carbon (soot)

(C) Sulfur dioxide

(D) Carbon dioxide

2011 - Q20

 

When charcoal reacts in the presence of oxygen, carbon monoxide and carbon dioxide are produced according to the following chemical reactions.

 

                                           C(s) + 1/2 O2(g) → CO(g)

 

                                            C(s) + O2(g) → CO2(g)

 

What would be the total mass of gas produced when 400 g of charcoal is reacted, assuming equal amounts are consumed in each reaction?

 

(A) 0.93 kg

(B) 1.2 kg

(C) 1.5 kg

(D) 2.5 kg

2013 - Q7

 

Which of the following is the correct equation for an INCOMPLETE combustion of octane?

2015 - Q10

 

Which of the equations correctly describes incomplete combustion?

2001 - Q25 (6 marks)

Explain the need for monitoring the products of a chemical reaction such as combustion.

2005 - Q23 (2 marks)

 

(a) What causes incomplete combustion? (1 mark)

 

(b) Write a balanced equation for the incomplete combustion of methane. (1 mark)

2007 - Q18 (3 marks)

 

Describe the role of a chemist employed in an industry or enterprise, and a chemical principle used by the chemist. (Choose an occupation other than teaching.)

2012 - Q33 (6 marks)

 

Chemists can assist in reversing or minimising the environmental problems caused by technology and the human demand for products and services.

 

With reference to this statement, assess the need for chemists to collaborate when monitoring the environmental impact of a named electrochemical cell.

2014 - Q25 (4 marks)

 

Under conditions of low oxygen levels, octane can undergo incomplete combustion according to the following chemical equation:

 

           2C8H18(l) + 17O2(g) → 6C(s) + 4CO(g) + 6CO2(g) + 18H2O(l)

 

(a) Explain the need to monitor this process. (2 marks)

 

(b) Calculate the mass of soot (C(s)) produced if 4.2 moles of octane are combusted in this way. (2 marks)

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