Question

x) Assertion: When we blow CO2 into a test – tube containing lime water, it turns milky

Reason: The change in colour shows the presence of CO2 in the exhaled air.


plz answer

(a) If both assertion and reason are true and reason is the correct explanation of assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of assertion.

(c) If assertion is true and reason is false.

(d) If assertion is false and reason is true.​

Answer 1

Answer:

A) if both assertion and reason are true and reason is the correct explanation of assertion

Answer 2

Both assertion and reason are true but reason is not the correct explanation of assertion.

• The test tube contains lime water $[Ca(OH)_{2}]$ which after the addition of carbon dioxide and also by removing water; gets converted into $CaCO_{3}$.

• During the process of respiration, as a byproduct; carbon dioxide is produced from the lungs during the exhalation of air.

• Carbon dioxide gas has a high partial pressure in the exhaled air.

• In a test tube, the exhaled air containing carbon dioxide is blown that reacts with the lime water present in the test tube then it is converted into limestone from lime water.

• The reaction occur as follow:

          $Ca(OH_{2}) + CO_{2}$ → $CaCO_{3} + H_{2}O$

• High concentration of carbon dioxide in the exhaled air turns the colour of lime water into milky white.

Hence, the correct option is b.