Question

) Calculate the molarity of a solution prepared by dissolving 117 g of sodium chloride (NaCl) in enough water to make 2.7 liters of solution.

Answer 1

The Molarity of the solution is given by:
$Molarity = \frac{moles-of-solute}{liters-of-solution}$ --- (A)

But NaCl, which is a solute, is given in grams.
Therefore, first, we need to convert grams into moles.

Molecular weight of NaCl = 58.44 grams/mole.

So,
117 grams * (moles/ 58.44 grams) = 2.00 moles of NaCl

Now that we have moles of NaCl, plug in the values in (A):
(A) => Molarity = (2 / 2.7 ) = 0.741 moles/litre

The correct answer is: 0.741 moles/litre = Molarity