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Minor Versionm

by Vishal Bhatt


Using sulphur powder and lime powder, we make acidic and basic solutions that are dilute enough to be safe and easily tested using litmus papers

Video Overview

    • Do not take large quantities of sulphur while burning. The gas produced on burning it is highly toxic.

    • Perform this experiment, preferably in an open space or a well ventilated room. Open all the windows if performed indoors.

    • Do not try inhaling the gas produced.

    • Be careful while handling match-sticks. Do not play with fire.

    • Do not touch calcium oxide and calcium hydroxide with your hands.

    • Do not ingest any materials.

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  1. Place the first bottle cap upside down .
    • Place the first bottle cap upside down .

    • Add the given sulphur to the cap, light a match-stick and ignite the sulphur with it.

    • Take the empty bottle (upside down) and screw it on to the cap.

    • Set aside for 15-20 minutes.

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    • The following steps have to be done very quickly to stop the gas from escaping.

    • Keeping the bottle inverted as before.

    • Remove the bottle cap. Clean the inner surface of the mouth of the bottle with a cloth.

    • Take the second cap and close the bottle with it.

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    • First, make sure that there is no sulphur remaining in the mouth of the bottle.

    • Keep the water ready in a beaker/glass.

    • Pour about 5 ml of water into the bottle containing the gas by un-capping and then re-capping the bottle as quickly as possible.

    • Shake well so that the gas dissolves in the water.

    • After 10-15 mins, test the contents of the bottle with a pH paper. Note down the pH based on the colour chart.

    Comments by Vishal:

    1) Instructions and photo are not matching. We should have one photo where we show pouring water in the bottle.

    2) One photo showing red colour on litmus paper. If we use pH paper, let us have one photo with blue-red litmus paper as well.

    Procheta Mallik - Reply

    • Test the content with blue litmus paper as well.

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    • Take out the given 5g of calcium oxide (CaO), also known as lime, and transfer it into a container.

    • Pour 10-20 ml of water into the container.

    • Stir the lime-water mixture thoroughly.

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    • Take a pH paper and dip it in the lime water.

    • Observe the colour change.

    • Note down the pH based on the colour chart.

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    • Perform pH paper / litmus test on both the water solutions.

    • Compare the strip with the pH chart and note down the pH.

    • Which of the two solutions is acidic and which basic?

    • What do you suspect are the chemicals being produced that are making the solutions acidic or basic?

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    • Too much gas escapes while opening and re-closing the bottle.

    • Sulphur burning doesn't occur for long enough.

    • Lime dissolves very poorly in water, so make sure you stir thoroughly before performing the litmus test.

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Finish Line

Vishal Bhatt

Member since: 04/26/2017

2,173 Reputation

49 Guides authored


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