Answer:
[tex]\boxed{\text{40 000 g}}[/tex]
Explanation:
We must convert formula units of Ni₃(PO₄)₂ to moles and then to grams.
Step 1. Convert formula units to moles
[tex]\text{Moles of Ni$_{3}$(PO$_{4}$)$_{2}$}\\= 6.58 \times10^{25}\text{ formula units Ni$_{3}$(PO$_{4}$)$_{2}$} \times \dfrac{\text{1 mol Ni$_{3}$(PO$_{4}$)$_{2}$}}{6.022 \times\ 10^{23} \text{ formula units Ni$_{3}$(PO$_{4}$)$_{2}$}}\\\\= \text{109.3 mol Ni$_{3}$(PO$_{4}$)$_{2}$}[/tex]
Step 2. Convert moles to grams
[tex]\text{Mass of Ni$_{3}$(PO$_{4}$)$_{2}$}\\\\= \text{109.3 mol Ni$_{3}$(PO$_{4}$)$_{2}$} \times \dfrac{\text{366.02 g Ni$_{3}$(PO$_{4}$)$_{2}$}}{\text{1 mol Ni$_{3}$(PO$_{4}$)$_{2}$}}\\\\= \text{378 g Ni$_{3}$(PO$_{4}$)$_{2}$}\\\text{The mass of Ni$_{3}$(PO$_{4}$)$_{2}$ is } \boxed{\textbf{40 000 g}}[/tex]
