Question

Find the molar concentration of $MgC{I}_2$ in solution, when 190 grams of $MgC{I}_2$ is dissolved in water and the total solution is 500 mL in volume?

• A. $4.0M$
• B. $2.0M$
• C. $8.0M$
• D. $16.0M$
• E. $12.0M$

Answer 1

The correct option is A $4.0M$

Molar mass of $MgC{l}_2=24.3+2\left(35.5\right)=95.3g/mol$
Number of moles is the ratio of mass to molar mass.
Number of moles of $MgC{l}_2=\frac{190g}{95.3g/mol}=1.994mol$
The molar concentration is the number of moles of solute present in 1 L of solution.
Molar concentration of $MgC{l}_2=\frac{1.994mol}{0.500L}=4.0M$