Question

How many moles are 1.20 x 1025 formula units of calcium iodide?

Answer 1

19.9 mol

Explanation:

Use Avogadro’s number to convert formula units of CaI₂ to moles of CaI₂.

1 mol CaI₂ ≡ 6.022 × 10²³ formula units CaI₂

Moles of CaI₂ = 1.20 × 10²⁵ × (1 /6.022 × 10²³)

Moles of CaI₂ = 19.9 mol