Respuesta :

Answer:

0.409 mol

Explanation:

The formula to find he number of moles is:

No. of moles = [tex]\frac{mass}{Mr}[/tex]

Mr of MgBr₂ = 24.3 + (79.9 × 2) = 184.1

Mass = 75.25g

So, no. of moles = [tex]\frac{75.24}{184.1}[/tex]

No. of moles = 0.409 mol [to 3 significant figures]