Molarity Quick Review and Practice Questions


Molarity is the measure of the concentration of a substance in a solution, given in terms of the amount of substance per unit volume of the solution.

Molarity questions are on the HESI and the NLN PAX –


Typical Question and solution     Practice Questions     Answer Key


How to Solve Molarity Questions

Molarity is also called, amount-of-substance concentration, amount concentration, substance concentration, or simply concentration.

The Molarity of a solution simply means the amount of moles contained in every liter of a solution. To better understand the concept of molarity of a solution it is necessary to first understand some related terms.

* A solute – is the substance that is being dissolved such as sugar or mercury.
* A solvent – refers to the liquid that the solute is being dissolved in.
* A solution – refers to the mixture of the solvent and the solute so that solution equals solvent plus solute.

The Molarity of the solution is thus a measurement of the molar concentration of the solute in the solution. The molarity of a solution is measured in moles of solute per liter of solution, or mol/liter. For example, if the molarity of a mercury solution is 1M, it simply means that there is 1 mole of sugar contained in every 1 liter of the solution.

The formula for molarity is = moles of solute/total liters of solution

Here is a typical question:

If 2 moles of salt is dissolved to form 1 liter of solution, calculate the molarity of the solution.

a. 1 M solution
b. 1.5 M solution
c. 2 M solution
d. 2.5 M solution

The formula for calculating molarity when the moles of the solute and liters of the solution are given is = moles of solute/ liters of solution.

Moles of Solute = 2 moles of sugar
Solution liters = 1 liters

The molarity of the solution = 2 moles of solvent/1 liters of solution = 2 M solution.

Continue reading “Molarity Quick Review and Practice Questions” »