Question

A chemist prepares a solution of iron(III) bromide by measuring out of iron(III) bromide into a volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's iron(III) bromide solution. Be sure your answer has the correct number of significant digits.

Answer 1

The question is incomplete, here is the complete question:

A chemist prepares a solution of iron (III) bromide $(FeBr_3)$ by measuring out 2.78 g of iron (III) bromide into a 50. mL volumetric flask and filling the flask to the mark with water.

Calculate the concentration in mmol/L of the chemists iron (III) bromide solution. Be sure your answer has the correct number of significant digits.

Answer: The concentration of iron(III) bromide solution is 0.19 M

Explanation:

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

We are given:

Given mass of iron(III) bromide = 2.78 g

Molar mass of iron(III) bromide = 298.6 g/mol

Volume of solution = 50. mL

Putting values in above equation, we get:

$\text{Molarity of solution}=\frac{2.78\times 1000}{298.6\times 50}\\\\\text{Molarity of solution}=0.19M$

Hence, the concentration of iron(III) bromide solution is 0.19 M