Answer:
2.29 × 10²³ formula units of MgCl₂
Step-by-step explanation:
Given data:
Mass of MgCl₂ = 36.2 g
Number of formula units = ?
Solution:
The given problem will be solved 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.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water = 6.022 × 10²³ formula units of water.
In 36.2 g of MgCl₂:
Number of moles = mass / molar mass
Number of moles = 36.2 g / 95.211 g/mol
Number of moles = 0.38 mol
1 mole = 6.022 × 10²³ formula units
0.38 mol / 1mol × 6.022 × 10²³ formula units
2.29 × 10²³ formula units of MgCl₂