How many formula units make up 22.6 g of magnesium chloride (mgcl2) ?

Formula Units = 1.42 * 10²³

Solution:

Step 1: Calculate Moles using following formula,

Moles = Mass : M. mass

As,

M. mass of MgCl₂ = 95.2 g. mol⁻¹

Putting values,

Moles = 22.6 g : 95.2 g. mol⁻¹

Moles = 0.237 mol

Step 2: Calculate number of Formula Units using following formula,

Formula Units = Moles * 6.022 * 10²³

Putting values,

Formula Units = 0.237 * 6.022 * 10²³

Formula Units = 1.42 * 10²³