Molarity

The Molarity calculator computes the molarity based on the number of moles of solute and the volume of solution.

INSTRUCTIONS: Choose units and enter the following:

• (m) Moles of Solute
• (k) Volume of Solution

Molarity (M): The molarity is returned in moles per liter.  However, this can be automatically converted to compatible units via the pull-down menu.

The Math / Science

The Molarity equation calculates the concentration of a solution and is one of the most commonly used methods of doing so in chemistry disciplines. The equation is as follows:

Molarity (M) = moles solute / liters solution

where:

• M = Molarity
• m = Moles of Solute = moles of the substance being dissolved
• k = Volume of Solution = the total volume of the solute and substance that dissolved the solute (usually water)

To prepare one liter of a one molar (1M) solution, one mole of solute is put into a 1 liter volumetric flask and then dissolved in a small amount of solvent (usually distilled water).  The solution is then diluted to the mark with solvent and mixed until all of the solute has dissolved. This task is performed routinely in chemistry labs ranging from general chemistry to physical chemistry.

Supplemental Material

• Khan Academy: Molarity vs. Molality

References

• Whitten, et al. "Chemistry" 10th Edition. Pp. 99