Chapter 5 : The Air Around Us

Chapter 5 : The Air Around Us

Aras rendah

1. What is the average percentage of nitrogen in the air?

A 0.03%

B 0.97%

C 21%

D 78%

2. The presence of carbon dioxide can be detected by using

A A red litmus paper

B a glowing wooden splinter

C hydrogen carbonate indicator

D water

3. Which of the following is true about the composition of inhaled air and exhaled air?

Composition

Inhaled air

Exhaled air

A

Water vapour

Less

More

B

Oxygen

21%

4%

C

Carbon dioxide

0.03%

16%

D

Nitrogen

78%

21%

4. Respiration increases the percentage of in the air.

A nitrogen

B oxygen

C inert gases

D carbon dioxide

5. What is the average percentage of oxygen in exhaled air?

A. 4%

B. 16%

C. 21%

D. 78%

6. A gas has the following characterisrics

. Odourless

. Colourless

. Very soluble in sodium hydroxide solution.

The gas is

A neon

B oxygen

C nitrogen

D carbon dioxide

7. Diagram shows the percentage composition of air.

Which gas A, B, C, and D supports combustion?

8. The information below shows some properties of a gas.

. Its extinguishes a burning splinter.

. It is very soluble in sodium hydroxide solution.

. It turns blue litmus paper red.

What is the gas?

A Oxygen

B Carbon dioxide

C Nitrogen

D Hydrogen

Aras sederhana

1. Gas X turns blue litmus paper to red. Gas X is.

A Oxygen

B Nitrogen

C Carbon dioxide

D Water vapour

2. The presence of water vapour in the air can be tested by

I anhydrous calcium chloride

II anhydrous copper (II) sulphate

III hydrogen carbonate indicator

A I and II only

B I and III only

C II and III only

D I, II and III

3. A type of gas has the following properties

Slightly soluble in water

Not soluble in sodium hydroxide solution

Neutral

The gas is.

A Oxygen

B Carbon dioxide

C Bromine

D Inert gases

4. Diagram shows a plastic bottle caving in when the air inside is sucked out.

This happens because

A the air pressure outside increases

B the air inside the bottle contracts

C the air pressure in the bottle decreases

D the temperature in the bottle decreases

5. Diagram shows a boy using a straw to suck a drink.

The drink is not sucked into the mouth because the air pressure in the straw is

A the same as the air pressure outside

B more than the air pressure outside

C less than the air pressure outside

D pressing on the drink.

6.

Figure shows two glass jars,X and Y,filled with air.Both jars have lighted candles placed in them.The candle in X is extinguished earlier than the candle in Y.This is because

A air in X has more water vapour

B air in Y has more water vapour

C air in X has more oxygen

D air in Y has more oxygen

7. Diagram shows the burning of charcoal.

The process above will produce

I heat

II light

III water

IV carbon dioxide

A I and II only

B I and III only

C I, II and IV only

D I, II, III, and IV.

Aras tinggi

1. Diagram 1 shows an experiment carried out to show respiration

Which of the test tubes record a change in the colour of hydrogen carbonate

indicator after an hour?

A P and Q

B P and R

C Q and R

D P, Q and R

2. Diagram 2 shows an experiment carried out to study respiration

Which of the following observations one may make after an hour?

Set P

Set Q

A

Thermometer reading increases

No change in thermometer reading

B

Red ink moves away from the test tube

Red ink moves towards the test tube

C

Thermometer reading decreases

Thermometer reading increases

D

Red ink moves towards test tube

Red ink moves away from test tube

3. Diagram shows an experiment.A gas jar is inverted over a lighted candle.

What would be observed after 15 minutes?

A The candle continues to burn and the water in the gas jar remains at the same level.

B The candle continues to burn and the water level in the gas jar rises up about one-

fifth its height.

C The candle is extinguisged and the water level in the gas jar moves up about one-

fifth its height.

D The candle is extinguisged but the water level in the gas jar remains at the same

level.

4. Three boiling tubes containing carbon dioxide are each inverted into glass through container water,sodium hydroxide and alkaline pyrogallol solution.Diagram shows the initial level of the liquids in each case.

What would be observed after 10 minutes?

A X and Y only

B X and Z only

C Y and Z only

D X , Y and Z

5. The greenhouse effect is the result of

A too much carbon dioxide being released into the atmosphere

B the solubility of carbon dioxide in rain water

C the melting of ice in the North Pole

D too much oxygen being used

Structure question

1. Compare and contrast oxygen and carbon dioxide. (Aras sederhana)

Similarities

Carbon dioxide

Differences

Oxygen

pH value

Taste

Effect on glowing wooden splint

Reaction with sodium hydroxide

Reaction with limewater

2. Diagram 3 shows the apparatus set up to show that living things released carbon dioxide during respiration.

a) What observation can be made after 30 minutes.(Aras rendah)

The bicarbonate indicator in test tube and test tube .. turns from to ............... colour.

b) Match the following variables by drawing lines(Aras sederhana)

0

0 0

0

c) What is the conclusion of the experiment?(Aras tinggi)

Living things release .

3. Search the word maze to find seven components of air (Aras sederhana)

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The seven components of air are : -

i) _______________________v) _____________________

ii) _______________________vi) _____________________

iii) _______________________vii) ____________________

iv) _______________________

4.Air is a mixture and not a compound. Based on the picture below, complete the

sentences which explain why air is a mixture. (Aras sederhana)

Air is a mixture of gases and also contains water vapour, __________________ and

dust. The components of air can be ____________________ physically. ________________ is used in respiration in living organisms. Oxygen is also needed for ________________. These processes release ________________ into the air. The carbon dioxide in air then is taken in by green plants for __________________, where food is made. The constituent gases in air may be mixed in different ______________. For example, the percentage of carbon dioxide is higher in industrial areas compared to a _______________ full of lush green trees.

5.Answer the following questions based on the diagram given. A lighted candle is placed inside an inverted gas jar in water as shown in the diagram 4

a) What hypothesis can be proposed? (Aras rendah)

_______________ of the volume (21%) of air consists of ______________

b) Match the following variables by drawing lines (Aras sederhana)

c) What happened to the flame of the candle and water level at the end of the experiment? (Aras Tinggi)

______________________________________________________________________________________________________________________________.

6. Ali inverted a gas jar over a lighted candle in a basin of water as shown in diagram

He recorded two observation as shown in table

Observation

P

The candle flame got smaller,spluttered and then went out

Q

When the flame went out,water rose in the gas jar and the water level in the glass basin dropped slightly.

(a)What inferences can you make based on the observations in table about P and Q ? (2marks)

(b)Describe two other observations in the experiment.(2 marks)

(c) (i)What gases are produced by the lighted candle? ( 2 marks )

(ii)Explain the presence of the gases you have given in 1(c)(i). (2 marks)

7. Diagram shows the beginning and end of an experiment to determine the percentage in air.In the experiment a gas jar is inverted over a lighted candle in a basin containing some water.The initial and final level of the water in the gas jar are noted.

(a)(i)What happens to the following at the end of the experiment?

1.The lighted candle.

2.The water level in the gas jar. (2 marks)

(ii)Explain the observation you have given in 2(a)(i)(2 marks)

(b)What conclusion can you draw from the experiment?(2 marks)

(c)Based on diagram above,calculate the percentage of oxygen in air. (2 marks)

8. Diagram shows a hydrocarbon,kerosene,burning in a gas jar containing water.

(a)Name elements found in kerosene. (2 marks)

(b)(i)Name the droplets of liquid formed on the sides of the gas jar.

(ii)How would you test for the presence of the liquis stated in (b)(i)?(2 marks)

(c)(i)What happen to the limewater in the gas jar?

(ii)What gas is produced when kerosene burns in air?(2 marks)

(d)Complete the word equation below to show the combustion of kerosene in air.

Kerosene + oxygen _________________+_________________ (1 mark)

(e)State the change in energy involved in the combustion of kerosene in air. (1 mark)

9. The pie chart in diagram below shows the percentage composition of air by volume.

(a)On diagram above,name the gas labeled X,Y and Z using the following words( 3 marks)

Oxygen

Nitrogen

Carbon dioxide

(b)State how gas Y and gas Z can be tested.( 2 marks)

Gas

Test

Y

Z

(c)What is the effect of deforestation on gas Y? (1 mark)

10. A student carried out an experiment to investigate the effect of quantity of air on the burning of candle.The time taken for the candle to extinguished in each of the bell jar is shown by the stopwatch in diagram below.

(Based on diagram above,record the stopwatch readings in the table.( 3 marks)

Bell jar

Stopwatch reading/s

P

Q

R

(b)Based on table above,draw a bar chart to show the stopwatch readings in the different bell jars. (3 marks)

(c)State the variables involved in this experiment. (3 marks)

(i)Manipulated variable:

(ii)Responding variable:

(iii)Controlled variable:

(d)Based on experiment,write a hypothesis.(1 mark)

(e)Predict the time taken for the candle to be extinguished if it is put in a bell jar which is bigger than P. (1 mark)

(f)Based on the experiment,what can you deduce about the meaning of combustion of a candle. (1 mark)

Diagram 1

Diagram 2

i) Constant variable

ii) Manipulated variable

iii) Responding variable

Presence of living things

Colour of the bicarbonate indicator

Air in the test tube

Burning

Proportions

Carbon dioxide

Photosynthesis

Garden

Separated

Microorganism

Particles

oxygen

Diagram 4

ii) Manipulated variable

iii) Responding variable

The increase in water level in the gas jar

i) Constant variable

Size of the gas jar

Burning of the candle