How many formula units of silver fluoride, AgF, are equal to 42.15 g of this substance?

2.05 × 10²³ formula units

Explanation:

Given data:

Mass of AgF =  43.15 g

Number of formula units = ?

Solution:

Number of moles of AgF:

Number of moles = mass/ molar mass

Number of moles = 43.15 g/ 126.87 g/mol

Number of moles = 0.34 mol

Now Number of formula units will be determine 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 formula units

0.34 mol × 6.022 × 10²³ formula units

2.05 × 10²³ formula units