How many moles of oxygen atoms are present in 0.25 moles of calcium carbonate, CaCO₃?

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Question

How many moles of oxygen atoms are present in 0.25 moles of calcium carbonate, CaCO₃?

Accepted Answer

0.75 — 75. Award 1 mark for correct reasoning. Each formula unit of CaCO₃ contains 3 oxygen atoms, therefore 1 mole of CaCO₃ contains 3 moles of oxygen atoms. 0.25 moles of CaCO₃ contains 0.25 × 3 = 0.75 moles of oxygen atoms. A is incorrect because it assumes only 1 oxygen atom per formula unit. B is incorrect because it assumes 2 oxygen atoms. D is incorrect due to multiplication error.

Answer

0.25

Answer

1.50

Answer

0.75

Answer

0.50

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