Question

What is the molarity of a solution prepared by dissolving 198 g of BaBr2 in 2.00 liters of solution?

Answer 1

Answer:

The molarity of the solution is 0.335 $\frac{moles}{liter}$

Explanation:

Molar concentration is a measure of the concentration of a solute in a solution, be it some molecular, ionic, or atomic species.

Molarity is the number of moles of solute that are dissolved in a certain volume and is calculated by:

$Molarity=\frac{number of moles of solute}{volume}$

Molarity is expressed in units $\frac{moles}{liter}$.

Being the molar mass of BaBr2 equal to 297.14 g/mole, that is to say that 1 mole contains 297.14 grams, the mass of 198 grams are contained in:

$198 grams*\frac{1 mole}{297.14 grams} = 0.67 moles$

So:

• number of moles of solute= 0.67 moles
• volume= 2 L

Replacing in the definition of molarity:

$Molarity=\frac{0.67 moles}{2 L}$

Solving:  

Molarity= 0.335 $\frac{moles}{liter}$

The molarity of the solution is 0.335 $\frac{moles}{liter}$