How many formula units make up 12.8 g of magnesium chloride ( mgcl2)? express the number of formula units numerically.

For 12.8 g there 0.807 × 10³ formula units.

Explanation:

Given data:

Mass of MgCl₂ = 12.8 g

Formula units for given mass = ?

Solution:

First of all we will calculate the number of moles.

Number of moles = mass/molar masss

Number of moles = 12.8 g/ 95.211 g/mol

Number of moles = 0.134 mol

According to the Avogadro number,

one moles = 6.022 × 10³ formula units

For 0.134 mol,

0.134 × 6.022 × 10³ formula units

0.807 × 10³ formula units

For 12.8 g there 0.807 × 10³ formula units.

it's c. elements are placed in rows based on how may valencies electrons have.