All Junior Cert Science Revised Syllabus posts
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    controls for experiments? dog lover

    what are the controls for the following experiments?:

    1) to show that there is carbon dioxide in air.

    2) to show that there is water vapour in air.

    3) to conduct a qualitative experiment to detect the presence of dissolved solids in water samples.

    4) to test water for hardness.

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      None of them need controls?

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      1) 2 test tubes - lime water in both. Breath in through A and out through B. B tyrns milky, A stays clear. A isnt really a control but more a way of demonstrating its the exhaled air that contains the CO2

      3) no control

      4) you are testing water for hardness - comparative experiment to test different samples of water

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