6. Complete Activity 6.6 (Page 63). Take a slender, clean test tube or a glass/plastic bottle. Make a hole in its lid and fix it on the bottle. Pour some freshly prepared lime water in the test-tube. Insert a plastic straw through the hole in the lid in such a way that it dips in lime water. Now blow gently through the straw a few times. Is there a change in the appearance of lime water? Can you explain this change on the basis of what you learnt in Chapter 6?
Answer:
The Activity 6.6 should be carried out in the following way after procuring the required materials:
Aim: To identify the gas which is present in the air we breathe out.
Materials Required: Slender, clean test tube or a glass/plastic bottle, freshly prepared lime water, plastic straw.
Procedure:
(i) Pour some freshly prepared lime water in the test tube.
(ii) Insert a plastic straw into the test tube such that it dips in the lime water.
(iii) Blow gently through the straw a few times and observe what happens.
Observation:
You will observe that after blowing a few times the appearance of the lime water turns milky white.
Conclusion:
Lime water turning milky is a standard test for carbon dioxide gas. When carbon dioxide is passed through lime water, calcium carbonate is formed, which gives the lime water the milky appearance. So, we conclude that the air we breathe out contains carbon dioxide.
“Complete Activity 6.6 (Page 63). Take a slender, clean test tube or a glass/plastic bottle. Make a hole in its lid and fix it on the bottle. Pour some freshly prepared lime water in the test-tube. Insert a plastic straw through the hole in the lid in such a way that it dips in lime water. Now blow gently through the straw a few times. Is there a change in the appearance of lime water? Can you explain this change on the basis of what you learnt in Chapter 6?” – Solved.
Related Links:
Solution to Extended Learning Question 1
Solution to Extended Learning Question 2
Solution to Extended Learning Question 3
Solution to Activity 6.1
Solution to Activity 6.2
Solution to Activity 6.3
Solution to Activity 6.4
Solution to Activity 6.5
Solution to Chapter 6 Respiration in Organisms
