A student prepared a stock solution by dissolving 20.0 g of KOH in enough water to make 150.mL of solution.She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution.What is the concentration of KOH for the final solution?
A)0)548 M
B)0)713 M
C)1)40 M
D)1)82 M

Question

Quizplus · Accepted Answer

First, calculate the molarity of the stock solution: Molar mass of KOH = 56.11 g/mol. Moles of KOH = 20.0 g / 56.11 g/mol = 0.356 mol. Molarity of stock solution = 0.356 mol / 0.150 L = 2.373 M. Then, use the dilution formula M1V1 = M2V2: (2.373 M)(0.015 L) = M2(0.065 L). Solving for M2 gives M2 = 0.548 M.

A Student Prepared a Stock Solution by Dissolving 20