Questions: A chemist prepares a solution of magnesium fluoride (MgF2) by weighing out 0.0122 g of magnesium fluoride into a 400 mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in g / L of the chemist's magnesium fluoride solution. Be sure your answer has the correct number of significant digits.

A chemist prepares a solution of magnesium fluoride (MgF2) by weighing out 0.0122 g of magnesium fluoride into a 400 mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in g / L of the chemist's magnesium fluoride solution. Be sure your answer has the correct number of significant digits.

Transcript text: A chemist prepares a solution of magnesium fluoride $\left(\mathrm{MgF}_{2}\right)$ by weighing out 0.0122 g of magnesium fluoride into a 400 . mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in $g / L$ of the chemist's magnesium fluoride solution. Be sure your answer has the correct number of significant digits.

Solution

Solution Steps

Step 1: Determine the Mass of Magnesium Fluoride

The mass of magnesium fluoride ($\text{MgF}_2$) used is given as 0.0122 g.

Step 2: Convert Volume from mL to L

The volume of the solution is given as 400 mL. To convert this to liters, use the conversion factor $1 \, \text{L} = 1000 \, \text{mL}$:

\[ 400 \, \text{mL} \times \frac{1 \, \text{L}}{1000 \, \text{mL}} = 0.400 \, \text{L} \]

Step 3: Calculate the Concentration in g/L

The concentration of the solution in grams per liter ($g/L$) is calculated by dividing the mass of the solute by the volume of the solution in liters:

\[ \text{Concentration} = \frac{\text{mass of } \text{MgF}_2}{\text{volume of solution in L}} = \frac{0.0122 \, \text{g}}{0.400 \, \text{L}} \]

\[ \text{Concentration} = 0.0305 \, \text{g/L} \]