Download App

CHEMISTRY [5 Mark Question Answer]

Air · ICSE STD 6 (ICSE - English Medium). 7 questions.

Questions

[5 Mark Question Answer]

🎯

Test yourself on this topic

7 questions · timed · auto-graded

Question 15 Marks
Draw a set-up for showing that oxygen gas is given out during photosynthesis. How will you test that the gas evolved is oxygen ?
Answer
Aim : To show that green plants produce oxygen during photosynthesis.
Materials required : A trough, a Hydrilla plant, a glass funnel, a test tube, water, wooden splinter.
Procedure:
1. Fill a trough to about three-fourths with water. Place a few cuttings of a Hydrilla plant in it and cover diem with a funnel.
2. Fill a test tube with water, cover its mouth with your thumb and place it over the stem of the,funnel.
3. Place the whole set-up in sunlight for a few hours.
Observation :
1. Bubbles of a gas are seen collecting in the test tube by the displacement of water. When the test tube is filled with the gas, remove it covering its mouth with the thumb.
2. Bring a glowing wooden splinter near the mouth of the test tube filled with the gas. The splinter starts burning with a bright flame.
Image
Conclusion : This shows that the gas in the test tube is oxygen. Thus, oxygen is produced during photosynthesis by green plants.

View full question & answer→
Question 25 Marks
State the similarities and differences between respiration and burning.
Answer
Respiration :
  1. Oxygen is required
  2. Carbon dioxide and water vapour are released.
  3. It is a natural and continuous process.
  4. It is a slow process.
  5. It takes place at body temperature (37 °C).
  6. Small amount of energy is released in the form of heat.
Burning (Combustion) :
  1. Oxygen is required.
  2. Carbon dioxide and water vapour are released.
  3. It is mostly an artificial and discontinuous process.
  4. It is a quick process.
  5. It takes place at high temperature.
  6. Large amount of energy is released in the form of heat and light.
View full question & answer→
Question 35 Marks
Describe an experiment to show that air is necessary for burning.
Answer

Aim : To show that air is necessary for burning.
Materials Required : A candle, a bell jar, a matchbox
Procedure :
1. Take a candle and fix it on a table.
2. Now light the candle. It bums and gives a flame.
3. Now cover the burning candle with a bell jar.
Observation : The candle under the jar continues burning for some time and then gets extinguished.
Conclusion : When the oxygen inside the inverted bell jar is used up, the candle gets extinguished. This proves that air (oxygen) is necessary for burning.
Image

View full question & answer→
Question 45 Marks
Describe an experiment to show that exhated air contains more carbon dioxide that inhaled air.
Answer
Aim : To show that exhaled air contains more carbon dioxide than inhaled air
Materials Required : Two conical flasks, lime water, corks, pinch clamps, glass tubes
Procedure :
1. Set up the apparatus as shown in figure.
2. Keeping pinch clamp A open and clamp B closed, such air in through opening C. This causes fresh air to be drawn into flask
3. Keeping pinch clamp A closed and clamp B open, below air out through opening C. This causes exhaled air to bubble into flask
Observation : The lime water in flask Q turns milky more rapidly than the lime water in flask P.
Conclusion : Exhaled air contains more carbon dioxide than inhaled air.
Image
View full question & answer→
Question 55 Marks
State the importance of the following components of air.
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
Answer
(a) Importance of nitrogen:
1. Controls rate of combustion of substances. In the absence of nitrogen, burning would be very fast and uncontrollable.

2. Helps in protein synthesis – Nitrogen helps in the formation of proteins which is essential for the growth and development of the plants.

(b) Importance of oxygen:
1. Supports combustion or burning of substances.
2. Essential for respiration by all living organisms. Respiration bums food in our body to release energy.

(c) Importance of carbon dioxide :
  1. Needed for photosynthesis by plants to manufacture their food.
  2. It is non-supporter of combustion so is used in fire – extinguishers.
  3. Used to make fizzy drinks (soda water and carbonated drinks)
  4. Used as refrigerant – Liquid and solid carbon dioxide (dry ice) are used as refrigerants and to store frozen foods.
View full question & answer→
Question 65 Marks
How will you show by an experiment that air contains carbon dioxide ?
Answer
Aim : To show that air contains carbon dioxide.
Materials Required : A boiling tube, a two-holed cork, delivery tubes, lime water.
Procedure:
1. Take some fresh lime water in a boiling tube. Close it with a two-holed cork, carrying two delivery tubes as shown in figure.
2. Suck in air through one delivery tube so that fresh air enters the lime water through the other tube.
Observation : After sucking air for some time, the lime water turns milky.
Conclusion : This shows that air contains carbon dioxide which turns lime water milky
.Image
View full question & answer→
Question 75 Marks
Define the following terms.
1. Respiration
2. Combustion
3. Photosynthesis
Answer
1. Respiration – Respiration is a chemical process that takes place in all living organisms by which they take in oxygen and use it to break down food and release energy, carbon dioxide and water vapour.
Image
2. Combustion – Combusion or burning is a chemical process in which substances combine with oxygen (of the air) and produce new substances called oxide along with energy in the form of heat and light.
3. Photosynthesis – Photosynthesis is the process by which green plants make their own food (in the form of carbohydrates) (from air) and water (absorbed from soil) in the presence of sunlight and with the help of chlorophyll.
Image
View full question & answer→
Generate Paper FreeAll Air topics
[5 Mark Question Answer] - CHEMISTRY STD 6 Questions - Vidyadip