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1.29 Which statement best explains why carbon monoxide is a pollutant gas?

    A It dissolves in rain water and causes acid rain.

    B It contribute to global warming.

    C It is a colourless and odourless gas.

    D It is absorbed in animal blood in preference of oxygen.

 

 

1.30 What is formed during the fermentation of glucose?

    A ethanol and carbon dioxide

    B ethanol and oxygen

    C ethane and carbon dioxide

    D ethane and oxygen

 

 

1.31 A transformer is used to convert a main 240 V supply into 12 V supply.

    The transformer has 2 000 turns on the primary coil.

    How many turns should there be on the secondary coil?

    A 20

    B 100

    C 167

    D 40 000

 

 

 

 

1.32 In which substance are the particles closest at room temperature?

    A ethanol

    B hydrogen

    C salt

    D water

 

 

1.33 The diagrams show the bonding in molecules of three different elements.

    Which of these molecules combine to form water?

    A Q and R only

    B Q and T only

    C R and T only

    D Q, R and T

 

 

1.34. Paul was given four different liquids and was asked to find out which one was an

    acid. Paul tested two liquids with blue litmus paper and two with red litmus paper.

    The results are shown below.

        

    Which liquid can Paul identify as definitely being an acid?

 

 

1.35. The equation describes a reaction which occurs in a blast furnace.

                                        Fe2O3 + 3CO → 2Fe + 3CO2

    Which substance is a reducing agent?

    A CO

    B CO2

    C Fe

    D Fe2O3

 

 

1.36. Which row in the table shows the correct composition of 100 cm3 of clean air?

    

 

 

1.37. Water from reservoirs is purified before is used for human consumption.

    What is the correct order of the water purification process?

    A chlorination → filtration → sedimentation

    B chlorination → sedimentation → filtration

    C sedimentation → chlorination → filtration

    D sedimentation → filtration → chlorination

 

 

1.38.The diagram shows a strip of ticker tape that has been pulled through a vibrating

    ticker timer by a battery operated toy car moving at constant speed.

    The arm of the ticker timer was making 50 dots every second.    

       

    What is the speed of the toy car?

    A 3.0cm/s

    B 5.0cm/s

    C 150cm/s

    D 1500cm/s

 

 

1.39. The diagram shows an object placed at four different positions. The dot is at the

    centre of gravity.

    Which position is the most stable?

 

 

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1 answer

Here are the answers to your questions based on the information provided:

1.29 Which statement best explains why carbon monoxide is a pollutant gas?

  • D It is absorbed in animal blood in preference of oxygen.
  • Explanation: Carbon monoxide binds to hemoglobin in blood more effectively than oxygen, which makes it a dangerous pollutant.

1.30 What is formed during the fermentation of glucose?

  • A ethanol and carbon dioxide
  • Explanation: Fermentation of glucose leads to the production of both ethanol and carbon dioxide.

1.31 A transformer is used to convert a main 240 V supply into 12 V supply. The transformer has 2 000 turns on the primary coil. How many turns should there be on the secondary coil?

  • B 100
  • Calculation: Using the transformer equation (Vp/Vs = Np/Ns), where Vp = primary voltage, Vs = secondary voltage, Np = number of turns in primary, and Ns = number of turns in secondary:
    • 240V / 12V = 2000 turns / Ns
    • Ns = (12V * 2000 turns) / 240V = 100 turns

1.32 In which substance are the particles closest at room temperature?

  • C salt
  • Explanation: In a solid like salt, the particles are very close together compared to liquids and gases.

1.33 Which of these molecules combine to form water?

  • C R and T only
  • Explanation: Water is formed by the combination of hydrogen (typically represented by one element) and oxygen.

1.34 Which liquid can Paul identify as definitely being an acid?

  • Depends on the results which are not shown here. Generally, a liquid that turns blue litmus paper red is definitely an acid.

1.35 Which substance is a reducing agent in the reaction Fe2O3 + 3CO → 2Fe + 3CO2?

  • A CO
  • Explanation: In this reaction, carbon monoxide (CO) is the reducing agent because it donates electrons to the iron oxide (Fe2O3) and reduces it to iron (Fe).

1.36 Which row in the table shows the correct composition of 100 cm3 of clean air?

  • Information about the table is needed to answer this question.

1.37 What is the correct order of the water purification process?

  • D sedimentation → filtration → chlorination
  • Explanation: The typical order for water purification involves sedimentation (removal of larger particles), then filtration (removal of smaller particles), followed by chlorination (disinfection).

1.38 What is the speed of the toy car?

  • B 5.0 cm/s
  • Calculation: If the ticker timer makes 50 dots per second and each dot represents a fixed distance of 0.1 cm, the speed can be calculated as:
    • Speed = Distance / Time = 5 cm / 1 sec = 5.0 cm/s

1.39 Which position is the most stable?

  • Again, further information or visuals would be needed to determine the most stable position of the object based on the center of gravity.

If you need further assistance or clarifications, feel free to ask!