Take some freshly prepared lime water in a test tube.
Blow air through this lime water.
Note how long it takes for the lime water to turn milky.
- ✅ Answer: It immediately turns lime water milky.
Use a syringe or pichkari to pass air through some fresh lime water taken in another test tube (Fig. 6.7).
Note how long it takes for this lime water to turn milky.
- ✅ Answer: It takes much time to turn the lime water milky.
What does this tell us about the amount of carbon dioxide in the air that we breathe out?