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    Struggling with this required practical question concerning volume of one mole of gas - the experiment was adding hydrochloric acid to magnesium carbonate and measuring the volume of carbon dioxide produced in the reaction.
    The expected volume of carbon dioxide at room temperature is 120cm3 but the students in the question got 108cm3.

    "f) A possible reason for the lower volume of carbon dioxide was that some of the gas escaped when the hydrochloric acid was added.
    A student suggested that this could have been avoided if the 50.0cm3 of hydrochloric acid was added from a tap funnel as shown in the diagram. When this experiment was carried out the volume of gas collected in the gas syringe was now much more than 120cm3.
    • Explain why.
    • Predict the volume of gas collected in the gas syringe."
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    I will throw down my gauntlet and help u poor student
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    May be because of unprocessed HCL left.
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    This is because the percentage yield = 90% therefore 10% is wasted gas
    The gas may also be no longer at room temp due to the funnel but not sure due to no diagram

    Are u alevel or gcse ?

    Since it would make more sense if i had an idea of the detail and complexity needed
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    (Original post by uselessdoctor)
    Struggling with this required practical question concerning volume of one mole of gas - the experiment was adding hydrochloric acid to magnesium carbonate and measuring the volume of carbon dioxide produced in the reaction.
    The expected volume of carbon dioxide at room temperature is 120cm3 but the students in the question got 108cm3.

    "f) A possible reason for the lower volume of carbon dioxide was that some of the gas escaped when the hydrochloric acid was added.
    A student suggested that this could have been avoided if the 50.0cm3 of hydrochloric acid was added from a tap funnel as shown in the diagram. When this experiment was carried out the volume of gas collected in the gas syringe was now much more than 120cm3.
    • Explain why.
    • Predict the volume of gas collected in the gas syringe."
    If you are pouring liquid down a thistle funnel you MUST displace the same volume of gas into the syringe.

    Can you now predict the extra volume?
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    (Original post by charco)
    If you are pouring liquid down a thistle funnel you MUST displace the same volume of gas into the syringe.

    Can you now predict the extra volume?
    I see now! So the new volume in the gas syringe will be 170cm3 because the 50cm3 of acid will displace 50cm3 of air in the flask, adding to the 120 already in there?
 
 
 
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