Is Matter Around Us Pure
Que 1. While chopping vegetables Sushila’s mother accidently injured her fingers due to which she began bleeding profusely. Sushila immediately applied alum on the cut part (wound). The bleeding stopped after some time.
(i) Mention the value shown by Sushila in the above case.
(ii) What is the role of alum used in the above case?
Ans.
(i) Presence of mind, knowledgeable.
(ii) Alum acts as a coagulant and helps in stopping bleeding.
Que 2. Anil and Roshan went to a restaurant to have dinner. Anil picked up the glass of water to drink but he immediately kept it back. He said, "The water was not fit for drinking."
Based on the above information answer the questions that follow:
(i) What could be the reason of it?
(ii) How could have been the water made fit for drinking? Name the process.
(iii) Which values are promoted by the restaurant people here?
Ans.
(i) Heavy suspended particles might be floating in the water served for drinking.
(ii) Water could have been made fit for drinking by adding alum to the water. The heavy particles of dissolved alum deposit on the finer suspended particles. The suspended particles become heavy and settle down at the bottom of the tank. This process is known as sedimentation.
(iii) Ignorance, carelessness, unhygienic conditions.
Que 3. In a hill station a group of tourists were going for a short tour by a jeep. The driver was repeatedly wiping the glass of front window as there was obstruction of view.
Answer the following questions based on the information given above.
(i) Why there was obstruction in view?
(ii) What precaution should be taken by the driver in the hilly area?
(iii) Write any two properties of it.
Ans.
(i) The obstruction in view was due to formation of a mixture known as smog created by smoke and fog, present in the atmosphere.
(ii) The driver should move in a slow pace with front lights on.
(iii) Smog is a mixture known as suspension.
Characteristics:
(i) The particle size in suspensions ranges from 10-3 cm to 10-5 cm.
(ii) The particles of suspension do not pass through filter paper.