Form 1 ScienceChapter 5

FORM 1 CHAPTER 5AIR AROUND US

1. Diagram 1.1 shows the percentages of gases found in the air.

(a) Label gas P, Q and R on the Diagram 1.

[3 marks]

(b) Give one use of

(i) gas Q : ………………………………………………………………………………………….

(ii) gas R : ………………………………………………………………………………………….

[2 marks]

(c) Diagram 1.2 shows a test on a gas. Which of the following gases, P, Q or R will show the results as shown in Diagram 1.2?

………………………………………………………………………………………………………

[1 mark]

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78%

0.03% 21%1%

R: …………………………….

P: ………………………….

Q: ………………………..

Diagram 1.1

Glowing wooden splinter

Gas Gas

Diagram 1.2

Form 1 ScienceChapter 5

2. Diagram 2 shows some ice cubes in a beaker. The beaker was left at room temperature. After a while, X is formed on the outer wall of the beaker.

(a) What is X?

……………………………………………………………………………………………………….

[1 mark]

(b) How do you test for X?

……………………………………………………………………………………………………….

[1 mark]

(c) Where does X come from?

………………………………………………………………………………………………………

[1 mark]

(d) Explain how X is formed.

………………………………………………………………………………………………………

………………………………………………………………………………………………………

[2 marks]

(e) What can you conclude from this activity?

………………………………………………………………………………………………………

[1 mark]

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Ice cubes

X

Beaker

Evaporating dish

Diagram 2

Form 1 ScienceChapter 5

3. (a) Diagram 3.1 shows two candles which were lit in two different containers

Diagram 3.1

(i) Based on your observations in Diagram 3.1, state the difference in the time taken for the candle to burn in Situation A and Situation B.

………………………………………………………………………………………………………

………………………………………………………………………………………………………[1 mark]

(ii) What inference can be made based on Situation A and Situation B in Diagram 3.1.

……………………………………………………………………………………………………..

….………………………………………………………………………………………………….[1 mark]

(iii) State one hypothesis based on your observations in Diagram 3.1.

………………………………………………………………………………………………………. ……………………………………………………………………………………………………….

[1 mark]

(b) A student carried out an experiment to investigate Situation A and Situation B. Diagram 3.2 shows an experiment to determine how the volume of air affects the time taken for the candle to burn.

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Situation A Situation B

Beaker P (250 mℓ)

Beginning End

Form 1 ScienceChapter 5

(i) Based on Diagram 3.2 record the time taken for the candles to burn in Table 3.3.

Beaker Time taken for candle to burn (s)

P

Q

R

Table 3.3

[3 marks]

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Beaker Q (500 mℓ)

Beginning End

Beaker R (1000 mℓ)

Beginning End

Diagram 3.2

Form 1 ScienceChapter 5

(ii) Based on the readings in Table 3.3, draw a bar chart to show the time taken for the candle to burn in different containers.

[2 marks](c) State the variables involved in this experiment.

Manipulated variable

Responding variable

Constant variable

[3 marks]

(d) Based on the experiment, state the relationship between the volume of air and the time taken for the candle to burn.

………………………………………………………………………………………………………

………………………………………………………………………………………………………[1 mark]

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Time taken for candle to burn (s)

Beaker

0P Q R

Form 1 ScienceChapter 5

4. Diagram 4 shows the combustion of a candle.

(a)(i) What can be observed about the limewater after a while?

……………………………………………………………………………………………………………

[1 mark]

(ii) Name the gas that causes the change in (a)(i).

………………………………………………………………………………………………………….

[1 mark]

(b)(i) After the candle has extinguished, X is formed on the inner surface of the filter funnel. What can be observed when X is tested with anhydrous cobalt chloride paper?

…………………………………………………………………………………………………………….

[1 mark]

(ii) From your observations in (b)(i), what can you conclude about X?

…………………………………………………………………………………………………………….

[1 mark]

(c) Candle is a compound. From the results, what are the elements found in candle? …………………………………………………………………………………………………………….

[1 mark]

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Filter funnel

Candle

Limewater

X

Diagram 4

Form 1 ScienceChapter 5

(d) Write an equation in words to show the combustion of candle.

[2 marks]

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+ +

Heat energy + Light energy+

Form 1 ScienceChapter 5

5. Diagram 5 shows an activity to compare the content of oxygen in inhaled air and exhaled air.

(a) (i) Which candle will burn for a longer time? ……………………………………………………………………………………………………

[1 mark]

(ii) Explain your answer in (a)(i)

…………………………………………………………………………………………………..

[1 mark]

(b) (i) During the burning of the candle, which component of the air does not change in volume?

……………………………………………………………………………………………………

[1 mark] (ii) Give one reason for your answer in (b)(i).

........................................................................................................................................

[1 mark]

(c) During the haze, the Air Pollutant Index is above 500 which is a sign that the air is bad for health.

(i) State one human activity that causes the haze.

.......................................................................................................................................

[1 mark]

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P Q

Inhaled air Exhaled air

Measuring cylinder

Cork

Water

Burning candle

Diagram 5

Form 1 ScienceChapter 5

(ii) Suggest what you should do if you have to go out of your house during the haze.

…………………………………………………………………………………………………..

[1 mark]

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