Mol dan Massa

A.   Jumlah mol Ca₃(PO₄)₂

\begin{equation*}
\begin{split}
n& = \frac{m}{Mr} \\\\
n & = \frac{62}{ (3 \times 40) + (2 \times 31) + (8 \times 16)} \\\\
n& = \frac{62}{310} = 0,2 \text{ mol } \ce{Ca3(PO4)2}
\end{split}
\end{equation*}

B.   Jumlah molekul Ca₃(PO₄)₂

\begin{equation*}
\begin{split}
n& = \frac{N}{N_A} \\\\
0,2& = \frac{N}{6,02 \times 10^{23}} \\\\
N& = 0,2 \times 6,02 \times 10^{23} \\\\
N& = 1,204 \times 10^{23} \: \text{molekul } \ce{Ca3(PO4)2}
\end{split}
\end{equation*}