Class 7 chemistry important questions with answers are provided here for Chapter 16 – Water: A Precious Resource. These important questions are based on the CBSE board curriculum and correspond to the most recent Class 7 chemistry syllabus. By practising these Class 7 important questions, students will be able to quickly review all of the ideas covered in the chapter and prepare for the Class 7 annual examinations.
Download Class 7 Chemistry Chapter 16 – Water: A Precious Resource Important Questions with Answers PDF by clicking on the button below.
Recommended Video
Water A Precious Resource – Complete Chapter
Class 7 Chapter 16 – Water: A Precious Resource Important Questions with Answers
Multiple Choice Type Questions
Q1. What is the name given to the level at which groundwater is found?
(a) Water table
(b) Water cycle
(c) Water level
(d) All of the above
Answer: (a) Water table
Explanation: The water table or ground water table is the top level of an underground surface at which the soil or rocks are eternally saturated with water.
Q2. Which of the following is a natural resource?
(a) River
(b) Glacier
(c) Lake
(d) All of the above
Answer: (d) All of the above
Explanation: Rivers, glaciers and lakes are natural resources.
Q3. When do we celebrate World Water Day?
(a) 21 March
(b) 22 March
(c) 21 May
(d) 22 May
Answer: (b) 22 March
Explanation: World Water Day is celebrated on 22 March every year to attract the attention of everybody towards the importance of conserving water.
Q4. Which of the following is considered the primary source of water?
(a) Rainwater
(b) Pond water
(c) River water
(d) All of the above
Answer: (a) Rainwater
Explanation: Rainwater is the primary source of water. It is considered a pure and fresh form of water. It fills up rivers and ponds and also collects as groundwater.
Q5. Which of the following is considered the purest form of water?
(a) Rainwater
(b) Pond water
(c) River water
(d) All of the above
Answer: (a) Rainwater
Explanation: Rainwater is considered to be the purest form of natural water as it directly comes from the condensation of water droplets. During vaporisation by the sun, the water evaporates from oceans, seas, and rivers, leaving behind all the impurities and salts.
True or False Type Questions
Q1. More than one-tenth of the population may face water scarcity.
Answer: False
Explanation: It is estimated that more than one-third of the people will face water scarcity within a few years. Hence, the above statement is false.
Q2. The ocean plays a crucial role in supplying water.
Answer: True
Explanation: Most water we use comes from rain and water trickling into the ground as groundwater. The water that evaporates from oceans is a significant source of rainwater. Thus, the ocean plays a crucial role in supplying water. Hence, the above statement is true.
Q3. Sea is a source of potable water.
Answer: False
Explanation: Potable water means drinking water. The sea contains saline water that is not suitable for drinking. Thus, it is not a source of potable water. Hence, the above statement is false.
Q4. Well is an example of surface water.
Answer: False
Explanation: Well is an example of underground water. It is formed by digging and drilling in underground aquifers. Thus, it is not surface water. Hence, the above statement is false.
Q5. Evaporation of water occurs only in sunlight.
Answer: False
Explanation: Water can also be evaporated by heating from any source apart from the sunlight. Hence, the above statement is false.
Fill in the Blanks Type Questions
Q1. Oceans and seas cover ______ of the earth’s surface.
Answer: Two third
Q2. People obtain groundwater through _____ and ______.
Answer: Well and tube well
Q3. Collecting and storing rainwater is called ______.
Answer: Water harvesting
Q4. ______ and ______ are responsible for cloud formation.
Answer: Evaporation and transpiration
Q5. The water in the oceans and seas has many ______ dissolved in it.
Answer: Salts
Match the Following Type Questions
Q1. Match the items of column A with those of column B.
| Column A | Column B |
| Caspian Sea | Stream of water moving along a concrete path |
| Tide | Strong seismic waves |
| Tsunami | Periodic rise and fall of water |
| Ocean current | Largest lake |
Answer:
| Column A | Column B |
| Caspian Sea | Largest lake |
| Tide | Periodic rise and fall of water |
| Tsunami | Strong seismic waves |
| Ocean current | Stream of water moving along a concrete path |
Q2. Match the items of column A with those of column B.
| Column A | Column B |
| Green vitriol | Permanent hardness in water |
| Paint | Hygroscopic |
| Magnesium chloride | Temporary hardness in water |
| Magnesium bicarbonate | Heptahydrate |
| Calcium oxide | Colloidal |
Answer:
| Column A | Column B |
| Green vitriol | Heptahydrate |
| Paint | Colloidal |
| Magnesium chloride | Permanent hardness in water |
| Magnesium bicarbonate | Temporary hardness in water |
| Calcium Oxide | Hygroscopic |
Very Short Answer Type Questions
Q1. What is solvent?
Answer: A substance that dissolves another substance completely to form a solution is called a solvent.
Q2. Why do we call water a universal solvent?
Answer: Water is known as a ‘universal solvent’ because it is capable of dissolving more substances.
Q3. Why does ice float on water?
Answer: Ice is lighter in weight than water. Therefore, it floats on water.
Q4. What is the water cycle?
Answer: The water cycle is the continuous movement of water on, above, and beneath the earth’s surface.
Q5. Name the process of the water cycle.
Answer: The processes involved in the water cycle are mentioned below.
1. Evaporation
2. Transpiration
3. Condensation
4. Precipitation
5. Surface runoff
Q6. What is a cloud?
Answer: A cloud is tiny droplets of water or ice crystals floating in the air.
Q7. What is bawris?
Answer: Bawris is one of the old rainwater management approaches.
Q8. Name any two water conservation techniques adopted in India.
Answer: Rainwater harvesting arid watershed management.
Short Answer Type Questions
Q1. What do you understand by the term evaporation?
Answer: The process of changing the liquid state of water to a gaseous state is called evaporation. For example, surface water on earth evaporates and comes down as rain.
Q2. What do you understand by the term condensation?
Answer: The process when water in its gaseous form, that is, water vapour, changes to its liquid form, that is, water, is known as condensation. It is the opposite of evaporation.
Q3. What are the sources of groundwater?
Answer: Rainwater, as well as water from other sources such as rivers and ponds, seeps through the soil, filling empty spaces and cracks deep beneath the ground. Infiltration is another process by which water seeps into the ground.
Q4. List the factors responsible for water table depletion.
Answer: The factors responsible for water table depletion are mentioned below.
1. Increasing population
2. Industrialisation
3. Agricultural activities
4. Deforestation
Q5. What do you understand by the term water table?
Answer: When rain falls, some rainwater seeps through the soil and collects on the non-porous rocks. This collected water is known as underground water, and the groundwater level is known as the water table. Groundwater is obtained on the surface by digging wells or tube wells.
Q6. What is water pollution?
Answer: Water pollution is the contamination of water sources by substances that render the water unfit for drinking, cooking, cleaning, swimming, and other activities. Chemicals, trash, bacteria, and parasites are all examples of pollutants.
Q7. What do you understand by the term rainwater harvesting?
Answer: Rainwater harvesting is collecting and storing rainwater for later use rather than letting it runoff. The rainwater harvesting system is one of the most effective and widely used methods for water conservation.
Q8. What is the significance of the water cycle?
Answer: Water is required to survive all living and nonliving organisms. The water cycle is critical because it ensures that water is available to all living organisms and regulates weather patterns on our planet. Water that falls on land collects in rivers and lakes, soil, and porous rock layers, and much of it flows back into the oceans to evaporate.
Q9. What is an aquifer?
Answer: Groundwater is sometimes stored between layers of hard rock. It is known as an aquifer. Aquifer water is pumped and extracted using hand pumps and tube wells.
Q10. What do you understand by the term drip irrigation?
Answer: Drip irrigation is a cost-effective method of water use. It allows water to drip slowly to the roots of plants, either above the soil surface or buried below the surface, to save water and nutrients. The goal is to direct water into the root zone while minimising evaporation. Drip irrigation systems use a network of valves, pipes, tubing, and emitters to distribute water.
Q11. How are plants responsible for water conservation?
Answer: The roots of plants and trees hold the soil tightly, slowing the flow of rainwater on land and improving its absorption by the soil. As a result, if we plant more trees, the soil will absorb more rainwater, preserving groundwater.
Q12. What do you understand by the term water management?
Answer: Water management is moving and controlling water resources to minimise damage to property and life while also maximising efficient, beneficial use. Water management refers to developing, optimising, and planning water resources through various practices governed by different policies and regulations.
When water is appropriately managed in dams and levees, the risk of flooding is reduced.
Q13. What do you understand by the term precipitation?
Answer: The sun’s heat vaporises water into vapour. This vapour cools down and condenses to become clouds. It may then fall on the earth’s surface in the form of rain, snow or sleet. This phenomenon of water falling back onto the earth’s surface in the form of rain, snow or sleet is called precipitation.
Q14. What is acid rain?
Answer: The sulphur dioxide and nitrogen dioxide in the air reacts with the water vapour in the atmosphere to form sulphuric acid and nitric acid. These acids flow down along with rain, which is known as acid rain.
Long Answer Type Questions
Q1. How can we conserve water?
Answer: There are several modes for conserving water. Here are some essential water conservation practices.
1. Taking baths in a bucket and avoiding showers.
2. Ensure water from overhead tanks does not overflow
3. Turn off the water while brushing our teeth.
4. Wash fruits and vegetables in a water bowl instead of under running water.
5. Using the water used to wash vegetables to water garden plants.
6. Use a bucket to wash vehicles rather than pipes.
7. Rainwater harvesting is one of the most effective water conservation methods. Rainwater can be saved in a variety of ways rather than being wasted.
Q2. What is the role of water in the life of plants and animals?
Answer: Water is used for various purposes, including agriculture, industry, cooking, cleaning utensils, bathing, washing clothes, and, most importantly, drinking.
Water is a valuable resource because our daily activities rely solely on water. Water can be found everywhere but is not always drinkable or usable. Even though the seas are abundant in water, we cannot drink or use it as it is saline. Water aids in the nutrition of animals and plants. Plants require water to absorb nutrients from the soil and produce food. Plants would die without water, and we would lose greenery. It, in turn, would mean the end of all life on earth because there would be no food, oxygen, or rainfall without plants. Thus, it is valuable.
Q3. What are the uses of water?
Answer: Water is used for the following purposes.
1. It is used for drinking, cooking, washing utensils, cleaning the floor, brushing teeth, bathing, washing clothes, flushing toilets, and watering plants in the home.
2. Animals also use it for drinking.
2. In agriculture, water is used to grow plants.
3. Water is used in manufacturing paper, cloth, medicines, and chemicals.
4. Electricity is generated using water.
5. Water from rivers and the sea aids in dispersing seeds from various plants and trees.
Q4. How do agricultural activities affect the water table?
Answer: Agriculture requires water. Groundwater, rainwater, and canal water are the primary agricultural water sources. Agriculture cannot entirely depend on rainwater, especially in drylands (where there is no rain). Canal water is also only available in a few locations.
An increasing population means an increased need for agriculture, which puts more pressure on groundwater. Hence, the groundwater is being used at an increasing rate, causing the water table’s depletion.
Q5. Explain the water cycle process with a labelled diagram.
Answer: The water cycle shows the continuous flow of water within the earth and the atmosphere. Water molecules are transferred from the oceans and land surface into the atmosphere by evaporation, dropped on the land as precipitation and moved back to the sea by rivers and groundwater. This endless circulation of water is known as the water cycle.
Q6. Why do plants need water?
Answer: 1. Plants require water for food preparation, germination, and growth to produce fruits and flowers.
2. Plants require water to translocate food to other parts of the plant.
3. Water is home to a large number of plants. Crops require water to grow. Water is essential for their survival because it provides nutrients and oxygen.
4. Rain washes away the dust and smoke deposited on leaves by vehicles and aids the stomata in exchanging gases.
Q7. Describe Ganga Action Plan in detail.
Answer: Ganga Action Plan is an ambitious plan to save the river Ganga. It was launched in 1985. It aimed to reduce the pollution levels in the river. However, the increasing population and industrialisation have already damaged the river beyond repair. The Government of India launched a new National Mission for Clean Ganga (NMCG) initiative in 2016.
Read Also:
- Importance of Water (H2O)
- Properties of Water: Physical and Chemical
- Chemical Formula for Water
- The Importance of Water
- Hard Water and Soft Water
- Water Questions
- Uses of Water
- Difference between Hard Water and Soft Water
- Properties of Water: Physical and Chemical
- Chemistry Concept Questions and Answers
- Chemistry Worksheets Class 7 on Chapter 16 Water a Precious Resource with Answers – Set 1
- Chemistry Worksheets Class 7 on Chapter 16 Water a Precious Resource with Answers – Set 2
- Chemistry Worksheets Class 7 on Chapter 16 Water a Precious Resource with Answers – Set 3
- Class 7 Chemistry Chapter 16 Water a Precious Resource MCQs
Recommended Videos
Water Class 7 Chemistry in One Shot
Water Cycle
Water Class 7 Science Chapter 16 – MENTI Quiz
Water Class 7 Science – Complete NCERT Solutions
