A student wants to prepare exactly 250 mL of a 0.500 M aqueous potassium hydroxide solution.What mass of potassium hydroxide (molar mass = 56.10 g/mol) must the student dissolve in the 250 mL of solution?

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Quizplus · Accepted Answer

To prepare a 0.500 M solution in 250 mL (0.250 L), use the formula: Molarity (M) = moles of solute / liters of solution. Rearranging to find moles: moles = Molarity × liters = 0.500 M × 0.250 L = 0.125 moles. The mass of KOH needed = moles × molar mass = 0.125 moles × 56.10 g/mol = 7.0125 g, which rounds to 7.01 g.

A Student Wants to Prepare Exactly 250 ML of a 0.500