What is the molarity of a solution that contains 40 grams of #NaOH# in 0.50 liter of solution?

1 Answer
Jun 5, 2016

2.0 Molar


In order to find the molarity of a solution, we use the following equation:

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The volume of the given solution has the proper units, but the amount of solute does not. We are given the mass of NaOH, not the number of moles. In order to find the number of moles of NaOH, you would divide the given mass by the molecular weight of NaOH, which is 39.997 g/mol.

Moles of NaOH = 40 g / 39.997 g/mol = 1.00 mol
Now all we have to do is divide that value by the volume to obtain the molarity like so:
Molarity = 1.00 mol / 0.50 L = 2.0 Molar