Answer:
9.72 grams of Br
Step-by-step explanation:
This is the salt: MgBr₂ (Magnesium bromide)
1 mol of MgBr₂ has 1 mol of Mg and 2 mol of Br
Molar mass MgBr₂ → 184.11 g/m
So the rule of three will be:
184.11 g of salt have 2 moles of Br
11.2 g of salt have (11.2 . 2)/184.11 = 0.122 moles of Br.
Molar mass Br = 79.9 g/m
Mol . molar mass = mass → 0.122 m . 79.9 g/m = 9.72 g