A student prepared a stock solution by dissolving 10.0 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)0.274 mol L^-1 B)0.356 mol L^-1 C)2.81 mol L^-1 D)3.65 mol L^-1

Question

Quizplus · Accepted Answer

1. Calculate the moles of KOH in the stock solution:
moles KOH = mass/molar mass = 10.0 g / 56.11 g/mol = 0.178 mol
2. Calculate the concentration of KOH in the stock solution:
concentration = moles/volume = 0.178 mol/0.150 L = 1.18 mol/L
3. Calculate the moles of KOH in the final solution:
moles KOH = concentration x volume = 1.18 mol/L x 0.015 L = 0.0177 mol
4. Calculate the concentration of KOH in the final solution:
concentration = moles/volume = 0.0177 mol/0.065 L = 0.274 mol/L

Therefore, the best choice is A because it gives the correct concentration for the final solution based on the given information.

A Student Prepared a Stock Solution by Dissolving 10