Question

how many formula units make up 12.2 g of magnesium chloride (mgcl₂)? express the number of formula units numerically. view available hint(s)

Explanation:

Step1: Calculate molar mass of MgCl₂

Molar mass = 24.305 g/mol (Mg) + 2×35.453 g/mol (Cl) = 95.211 g/mol

Step2: Find moles of MgCl₂

Moles = $\frac{mass}{molar\ mass}$ = $\frac{12.2\ g}{95.211\ g/mol}$ ≈ 0.1281 mol

Step3: Calculate formula units

Formula units = moles × $N_A$ = 0.1281 mol × $6.022×10^{23}$ mol⁻¹ ≈ $7.71×10^{22}$

Answer:

$7.71×10^{22}$