MediumChemistryHigh School (11–12)Atoms and Molecules › The Mole ConceptNumerical

A stick of chalk is 10.0 g of calcium carbonate, CaCO₃, of molar mass 100.09 g mol⁻¹.

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A stick of chalk is $10.0$ g of calcium carbonate, $\text{CaCO}_3$ , of molar mass $100.09\ \text{g mol}^{-1}$ . How many moles of calcium carbonate is it, and how many oxygen atoms does it hold?

Need a reminder? The key ideaShow

One mole is $6.022 \times 10^{23}$ particles, the Avogadro constant $N_A$ . The molar mass $M$ in g/mol has the same number as the molecular mass in u. The amount is $n = \dfrac{m}{M}$ , and the number of particles is $N = n \times N_A$ .

The worked solution

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A stick of chalk is 10.0 g of calcium carbonate, CaCO₃, of molar mass 100.09 g mol⁻¹.

The worked solution

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