CAIE A Level Chemistry 9701 · Atoms, molecules and stoichiometry
A student compares 1 mol of oxygen gas, , with 1 mol of hydrogen gas, , and finds that the oxygen sample has the greater mass. The student concludes that one mole of oxygen contains more molecules than one mole of hydrogen.
Explain why this conclusion is incorrect.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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