Explain Activity 6.4 NCERT class 10 science Life processes


Activity 6.4 NCERT class 10 science chapter 6 Life processes

activity 6.4 Life processes NCERTBrief procedure: Activity 6.4 asks us to blow air from the mouth into a solution of lime water and compare the result with air blown using syringe or pichkari.


When we blow Air through mouth it turns lime water milky instantaneously. While when we blow air through syringe or pichkari, it takes a lot of time and effort to turn the lime water milky.


Our body cells produce carbon dioxide through oxidation of food. This gas is exhaled outside through the lungs. Lime water reacts with CO2 to form an insoluble precipitate. This turns lime water milky.

Ca(OH)2(aq)       +     CO2(g)   ——–> CaCO3(s)

(Lime)                                             (Insoluble Precipitate)

When syringe or pichkari is used, atmospheric air is pushed through the lime water. Atmospheric air contains very less amount of CO2. As a result lime water do not turn milky or takes a lot of effort.


This experiment demonstrates that our lung exhales carbon dioxide..

For more details, you can visit the related article from Education.com.

Next: Experiment to demonstrate yeast produces carbon dioxide. Activity 6.5.

See also: Experiment to see the effect of saliva on starch: Activity 6.3.

9 thoughts on “Explain Activity 6.4 NCERT class 10 science Life processes”

  1. This is OSM…………..
    I want to suggest read all activities from this.
    This is excellent site for activities of science ncert.

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