Question

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

Answer 1

Answer:

1.99 x 10²³ formula units

Explanation:

Given parameters:

Mass of AgF  = 42.15g

Unknown:

The amount of formula units

Solution:

To solve this problem, we set out by find the number of moles in this compound from the given mass.

   Number of moles  = $\frac{mass}{molar mass}$

molar mass of AgF  = 107.9 + 19  = 126.9g/mol

  Number of moles  = $\frac{42.15}{126.9}$   = 0.33 moles

       1 mole of a substance =  6.02 x 10²³ formula units

         0.33 moles of AgF  = 0.33 x 6.02 x 10²³  = 1.99 x 10²³ formula units