Question

How many anions are there in 3.50 g of MgBr₂?

Answer 1

To find the number of anions in 3.50 g of MgBr₂, calculate the moles of MgBr₂ and then determine the moles of Br- ions, giving you 0.038 moles of Br- ions.

Step-by-step explanation:

To determine how many anions are present in 3.50 g of MgBr₂, we need to follow these steps:

1. Find the molar mass of MgBr₂, which is 24.305 (Mg) + 2 × 79.904 (Br) = 184.113 g/mol.
2. Calculate the number of moles of MgBr₂ in 3.50 g:
   3.50 g MgBr₂ × (1 mol / 184.113 g) = 0.019 moles of MgBr₂.
3. Since each formula unit of MgBr₂ contains two bromide Br⁻ ions, calculate the number of moles of Br⁻ ions:
   0.019 moles MgBr₂ × 2 Br⁻/mol = 0.038 moles of Br⁻ ions.

Therefore, there are 0.038 moles of Br⁻ ions in 3.50 g of MgBr₂.