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Minor Versionm

by Kailash NR


We turn a mixture of clear lime-water (calcium hydroxide) turbid by blowing into it through a straw, thanks to the formation of calcium carbonate, which precipitates in the water.



    • Do not inhale Lime powder

    • Protect your eyes from Lime powder

    • Do not Ingest lime water while blowing into it

    • Do not blow hard into the test tube

    • Wash your hands thoroughly after conducting the experiment

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  1. Take a cup of water and add few grams of Lime powder to it.
    • Take a cup of water and add few grams of Lime powder to it.

    • Stir the solution and leave it for 10-15 minutes.

    • Now, a Milky white solution will be observed on the top , while lime particles will be settled at the bottom.

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    • Cut a Plastic bottle in the middle.

    • Place the upper part of the bottle inverted into the lower part

    • Place the filter paper like a funnel over the mouth of the plastic bottle's inverted upper part.

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    • Slow and diligently pour the milky white solution over the filter paper

    • The filtered solution will be collected at the lower part of the bottle.

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    • Take enough filtered solution in a test tube so that you can dip a litmus strip

    • Dip a Red litmus strip into the filtered solution.

    • The Litmus paper will turn blue confirming that lime solution is basic.

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    • Using straw, gently blow into the clear solution in the test tube.

    • If you blow hard into the solution, you will end up spilling the lime water all over you

    • Blow into the solution till it turns into milky white.

    • This is because, the air we breathe out is nothing but carbon dioxide.

    • The carbondioxide reacts with Ca(OH)2 (lime water ) to form CaCO3.


    1) Milky color not visible.

    2) Test tube is dirty.

    3) Use plastic bottle/cup instead of test tube. It is not necessary and children may not have access to test tubes.

    4) Also, filter paper not necessary. Just pour out from top.

    Procheta Mallik - Reply

    • Dip a Blue litmus strip in the milky white solution.

    • The colour of the litmus strip will remain the same

    • You can tilt the test tube to get the litmus strip dipped

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    • Dip a Red litmus strip into the milky white solution.

    • If the solution is not milky white, blow into it using straw so that it turns to milky white

    • The Red litmus strip will not change colour

    • Since both Red and blue litmus strips does not change their colour, it confirms that the solution is Neutral !

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    • Pour the lime solution directly over filter paper so that the solution gets filtered properly

    • The litmus tests have to be done immediately after blowing into the filtered solution

    • Have the filtered solution only about 1/3 of the test tube so that it does not spill when you blow into it

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Finish Line

Kailash NR

Member since: 05/02/2017

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67 Guides authored


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