What is molar concentration (molarity) of 20% (weight/ volume) glycerin solution.

Solution:

Molar concentration = number of moles/ volume of solution in liters.

20% = 20 grams/ 100 ml solution.

20% = 200 grams/ 1000 ml solution = 200 g/ liter.

Number of moles = mass/ molar mass

Molar mass ( molecular weight ) of glycerin (glycerol) = 92.1 g/ mole.

Number of moles = 200 g/ (92.1 g/ mole) = 2.17 mole.

Molar concentration = 2.17 mole/ 1 liter = 2.17 M.

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