Molarity is calculated by dividing the number of moles of a solute by the number of liters of solution. The calculation is fairly straightforward with one volume present. Multiple volumes will change the calculation, but fortunately, under the normal assumptions of the molarity equation, the change is slight. Simply add the multiple volumes together to get the total volume of the solution in liters, and let this number serve as the denominator in the molarity equation.
Instructions
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1
Divide the mass of the solute in grams by the molar mass of the solute (grams/mole) to calculate the number of moles of solute.
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2
Divide the mass of the solute in grams by the density of the solute in grams per liter to calculate the volume of the solute.
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3
Add the volumes of the solute and the multiple solvents together in liters.
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4
Divide the number calculated in Step 1 by the number calculated in Step 3 to calculate molarity in moles per liter.