How many moles are there in 25 g of CaCO₃? (molar mass 100 g/mol)
Answer and explanation
Correct answer: D. 0.25 mol
- Step 1: Moles = mass ÷ molar mass. Step 2. 25 ÷ 100 = 0.25 mol. Answer: 0.25 mol. Why not the others: 2500 mol is what you get if you multiply the mass by the molar mass. 4 mol is what you get if you invert the ratio. -75 mol is what you get if you subtract the molar mass.
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