Question 9:
Diagram 8 shows a usage of ethanol in daily life.
(a) Based on Diagram 8, state the colour of the flame. [1 mark]
(b) A woman uses a make up cleanser that contains alcohol to remove oil-based make-up.
State the role of alcohol in the situation.
[1 mark]
(c) Table 4 shows the characteristics of ethanol and a hydrocarbon compound P which can be used as a fuel.
Based on Table 4, choose a fuel which is more environmental friendly.
Give your reason.
[2 marks]
(d) You want to produce alcohol at home as fuel for a spirit lamp. You are given a bowl of rice, yeast, water and an empty bottle.
Write the steps to produce the alcohol.
1. ……………..
2. ……………..
3. ……………..
4. The mixture is kept in a dark place for a week.
5. Open the bottle cap every two days.
[3 marks]
Answer:
(a) Blue
(b) Alcohol acts as a solvent to dissolve oil-based make-up.
(c) The more environmentally friendly fuel is ethanol.
Reason:
– Ethanol undergoes complete combustion, so it produces less smoke and toxic gases.
– Hydrocarbon compound P undergoes incomplete combustion which produces soot and carbon monoxide.
(d)
1. Put the rice into the empty bottle.
2. Add yeast and water into the bottle.
3. Shake or stir the mixture well and close the bottle.
Diagram 8 shows a usage of ethanol in daily life.
(a) Based on Diagram 8, state the colour of the flame. [1 mark]
(b) A woman uses a make up cleanser that contains alcohol to remove oil-based make-up.
State the role of alcohol in the situation.
[1 mark]
(c) Table 4 shows the characteristics of ethanol and a hydrocarbon compound P which can be used as a fuel.
Based on Table 4, choose a fuel which is more environmental friendly.Give your reason.
[2 marks]
(d) You want to produce alcohol at home as fuel for a spirit lamp. You are given a bowl of rice, yeast, water and an empty bottle.
Write the steps to produce the alcohol.
1. ……………..
2. ……………..
3. ……………..
4. The mixture is kept in a dark place for a week.
5. Open the bottle cap every two days.
[3 marks]
Answer:
(a) Blue
(b) Alcohol acts as a solvent to dissolve oil-based make-up.
(c) The more environmentally friendly fuel is ethanol.
Reason:
– Ethanol undergoes complete combustion, so it produces less smoke and toxic gases.
– Hydrocarbon compound P undergoes incomplete combustion which produces soot and carbon monoxide.
(d)
1. Put the rice into the empty bottle.
2. Add yeast and water into the bottle.
3. Shake or stir the mixture well and close the bottle.
Question 10:
Diagram 9 shows the structures in the human skeletal system.
(a) State the name of bone P. [1 mark]
(b) Structure Q is broken caused by an accident. An early treatment has been given by wrapping wooden sticks on that part.
State the purpose of the action. [1 mark]
(c) Obesity problem causes someone to feel pain at structure R while moving. A doctor advises him to reduce body mass.
Explain the effect on the knee if he does not follow the doctor’s advice. [2 marks]
(d) A woman fell down from the stairs and sprained her leg. By using the carpentry tools and the following materials, you are required to create a tool to help the woman to walk.
In the space provided, sketch and label your tool and explain how the tool can help the woman to walk.
Sketch and label your tool in the space provided. [2 marks]
Explanation: [1 mark]
Answer:
(a) Femur
(b) – To prevent the broken bone from moving.
– To support and stabilise the broken bone.
(Any one answer)
(c) – The cartilage in the knee will become more worn out and damaged due to excessive body weight pressure.
– Friction between the bones increases, causing knee pain and difficulty in movement.
(d)
Explanation:
The underarm crutch helps the woman move more steadily and prevents the sprained leg from bearing too much weight. The wooden handle makes it easier for the woman to hold the crutch while walking.
Diagram 9 shows the structures in the human skeletal system.
(a) State the name of bone P. [1 mark](b) Structure Q is broken caused by an accident. An early treatment has been given by wrapping wooden sticks on that part.
State the purpose of the action. [1 mark]
(c) Obesity problem causes someone to feel pain at structure R while moving. A doctor advises him to reduce body mass.
Explain the effect on the knee if he does not follow the doctor’s advice. [2 marks]
(d) A woman fell down from the stairs and sprained her leg. By using the carpentry tools and the following materials, you are required to create a tool to help the woman to walk.
In the space provided, sketch and label your tool and explain how the tool can help the woman to walk.
Sketch and label your tool in the space provided. [2 marks]
Explanation: [1 mark]
Answer:
(a) Femur
(b) – To prevent the broken bone from moving.
– To support and stabilise the broken bone.
(Any one answer)
(c) – The cartilage in the knee will become more worn out and damaged due to excessive body weight pressure.
– Friction between the bones increases, causing knee pain and difficulty in movement.
(d)
Explanation:
The underarm crutch helps the woman move more steadily and prevents the sprained leg from bearing too much weight. The wooden handle makes it easier for the woman to hold the crutch while walking.