What is the concentration of an aqueous solution that contains 1.5 moles of NaCl in 500. milliliters

June 2018 NY Regents Chemistry Exam

42 What is the concentration of an aqueous solution that contains 1.5 moles of NaCl in 500. milliliters of this solution? (1) 0.30 M

(2) 0.75 M (3) 3.0 M

(4) 7.5 M

Solution: Table T on the Reference Table provides the formula for molarity

molarity = moles of solute/liters of solution

Notice, that we are given milliliters and not liters. We need to first convert milliliters into liters.

500ml/1000 = 0.500 L

M = 1.5 moles/0.500 L

M=3.0 M

Answer: 3

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