Chemistry 9th Chap 11 : Topic 10 - Maryam Publications

Chemistry Chapter 11 : Topic 10

Pollution Exposure Protection

1 / 15

A student wears a cloth mask while riding a motorcycle on a dusty road, but still experiences irritation due to smoke from vehicles. Which statement best explains why this happens?

A) Vehicle smoke contains only oxygen and nitrogen which cannot harm the body.

B) Cloth masks mainly reduce large dust particles but may not effectively block harmful gases and very fine pollutants.

C) Dust particles are more dangerous than smoke, so smoke does not need filtration.

D) Cloth masks can filter all harmful gases and smoke particles completely.

2 / 15

Which of the following situations best shows the importance of checking the Air Quality Index (AQI)?

A) Determining the boiling point of water in laboratories.

B) Calculating the density of gases in the atmosphere.

C) Deciding whether outdoor exercise is safe during heavy smog conditions.

D) Measuring the amount of oxygen dissolved in river water.

3 / 15

A carbon monoxide (CO) detector installed in a room suddenly starts ringing at night. What is the most appropriate reason for this warning?

A) Humidity in the room has become too high.

B) Excess oxygen is present in the room.

C) Carbon monoxide concentration has increased to a dangerous level.

D) Nitrogen gas has leaked into the room.

4 / 15

Why is carbon monoxide considered more dangerous than carbon dioxide in enclosed spaces?

A) Carbon monoxide has a pleasant smell that attracts people.

B) Carbon monoxide binds with hemoglobin in blood, reducing oxygen transport.

C) Carbon monoxide reacts strongly with water vapour in air.

D) Carbon monoxide increases the amount of oxygen in blood.

5 / 15

Which type of mask is generally more effective in reducing exposure to fine smoke particles and harmful pollutants?

A) Plastic face shield only

B) Loose woolen scarf

C) Decorative cotton mask

D) N95 respirator mask

6 / 15

During winter smog, the AQI of a city reaches a “hazardous” level. What should people do to reduce exposure to pollutants?

A) Increase outdoor sports activities.

B) Keep windows open continuously.

C) Burn more fuel indoors to keep the air warm.

D) Limit outdoor exposure and wear protective masks when necessary.

7 / 15

Which household appliance is most likely to require a carbon monoxide detector nearby for safety?

A) Refrigerator

B) Gas heater

C) Electric fan

D) LED television

8 / 15

A student notices that the AQI is very low on a particular day. What does this most likely indicate?

A) Air pollution level is low and the air is relatively cleaner.

B) Air pressure has suddenly increased.

C) Oxygen concentration in air has completely disappeared.

D) Harmful gases are at their maximum level.

9 / 15

Which statement correctly explains the role of masks in polluted environments?

A) Masks chemically destroy all pollutants present in air.

B) Masks reduce the amount of harmful particles inhaled into the lungs.

C) Masks prevent sunlight from entering the respiratory tract.

D) Masks convert carbon dioxide into oxygen.

10 / 15

Why should generators not be operated inside closed rooms without ventilation?

A) Generators consume nitrogen gas rapidly.

B) Generators increase humidity to harmful levels.

C) Generators may release carbon monoxide that can accumulate dangerously indoors.

D) Generators produce excessive oxygen gas indoors.

11 / 15

Which of the following best describes the purpose of an Air Quality Index (AQI)?

A) To determine the percentage of hydrogen in the atmosphere.

B) To measure underground water contamination only.

C) To indicate how polluted the air is and its possible health effects.

D) To measure the brightness of sunlight during daytime.

12 / 15

A person living near a busy industrial area wants to reduce daily exposure to pollutants. Which combination would be most effective?

A) Wearing an N95 mask outdoors and checking AQI regularly.

B) Ignoring AQI reports and keeping windows open at all times.

C) Using perfumes to cover polluted air smell.

D) Burning coal indoors to neutralize smoke.

13 / 15

Why are children and elderly people advised to stay indoors during severe smog conditions?

A) They are generally more sensitive to harmful pollutants and respiratory problems.

B) Their bodies require more nitrogen gas.

C) Smog mainly affects healthy adults only.

D) Their lungs can completely absorb smoke particles.

14 / 15

Which condition may indicate the possible presence of carbon monoxide indoors?

A) Increase in oxygen concentration in air

B) Strong smell and visible yellow smoke only

C) Continuous ringing of a CO detector despite no visible smoke

D) Formation of water droplets on windows only

15 / 15

A city administration advises citizens to use public transport during days of poor AQI. What is the main purpose of this advice?

A) To increase carbon monoxide production intentionally.

B) To raise the oxygen level above normal atmospheric concentration.

C) To reduce the number of vehicles releasing pollutants into the atmosphere.

D) To increase the temperature of the city environment.

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