Question

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

Answer 1

2.05 × 10²³ formula units

Given data:Mass of AgF =  43.15 gNumber of formula units = ?Solution:Number of moles of AgF:Number of moles = mass/ molar massNumber of moles = 43.15 g/ 126.87 g/molNumber of moles = 0.34 molNow 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 number1 mole = 6.022 × 10²³ formula units0.34 mol × 6.022 × 10²³ formula units2.05 × 10²³ formula units