What is the mass of 0.5 moles of calcium carbonate, CaCO3? (Ca = 40, C = 12, O = 16)
Answer and explanation
Correct answer: C. 50 g
- Step 1: Formula mass is 40 + 12 + 3 x 16 = 100. Step 2. Mass = moles x Mr = 0.5 x 100 = 50 g. Answer: 50 g. Why not the others: The other answers use the wrong value of Mr or forget to multiply by the moles.
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