How many atoms of iodine are in 12.75g of CaI2

0.5 * 10²³ atoms of iodine

Explanation:

Given dа ta:

Mass of calcium iodide = 12.75 g

Number of atoms of iodine = ?

Solution:

First of all we will calculate the number of moles of calcium iodide.

Number of moles = mass / molar mass

Number of moles = 12.75 g / 293.9 g/mol

Number of moles = 0.04 mol

In one mole of calcium iodide there are two moles of iodine.

Thus in 0.04 moles:

0.04 mol * 2 = 0.08 moles of iodine

Now we will use the Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms, ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 * 10²³ is called Avogadro number.

1 mole = 6.022 * 10²³ atoms

0.08 moles of iodine * 6.022 * 10²³ atoms / 1 mol

0.5 * 10²³ atoms of iodine.