How many formula units of CaO are in 32.7 g of CaO?

3.51× 10²³ formula units

Explanation:

Given data:

Mass of CaO = 32.7 g

Number of formula units = ?

Solution:

First of all we will calculate the number of moles.

Number of moles = mass/molar mass

Number of moles = 32.7 g/ 56.1 g/mol

Number of moles = 0.583 mol

Number of formula units:

1 mole = 6.022 × 10²³ formula units

0.583 mol ×  6.022 × 10²³ formula units / 1 mol

3.51× 10²³ formula units

The number 6.022 × 10²³ is called Avogadro number.

the answer is c.the valence of the atoms combine .