Question

A chemist prepares a solution of potassium permanganate by measuring out 26. g of potassium permanganate into a 350. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's potassium permanganate solution. Be sure your answer has the correct number of significant digits.

Answer 1

Answer:

The concentration of this potassium permanganate solution is 0.470 mol/L or 0.470 M

Explanation:

Step 1: data given

Mass of  potassium permanganate = 26.0 grams

Molar mass of potassium permanganate = 158.034 g/mol

Volume = 350 mL = 0.350 L

Step 2: Calculate moles potassium permanganate

Moles KMnO4 = mass KMnO4 / molar mass KMnO4

Moles KMnO4 = 26.0 grams / 158.034 g/mol

Moles KMnO4 = 0.1645 moles

Step 3: Calculate concentration of KMnO4 solution

Concentration KMnO4 = moles KMnO4 / volume

Concentration KMnO4 = 0.1645 moles / 0.350 L

Concentration KMnO4 = 0.470 M

The concentration of this potassium permanganate solution is 0.470 mol/L or 0.470 M

Answer 2

Answer:

0.471 mol/L

Explanation:

First, we'll begin by by calculating the number of mole of KMnO4 in 26g of KMnO4.

This is illustrated below:

Molar Mass of KMnO4 = 39 + 55 + (16x4) = 39 + 55 + 64 = 158g/mol

Mass of KMnO4 from the question = 26g

Mole of KMnO4 =?

Number of mole = Mass/Molar Mass

Mole of KMnO4 = 26/158 = 0.165mole

Now we can obtain the concentration of KMnO4 in mol/L as follow:

Volume of the solution = 350mL = 350/1000 = 0.35L

Mole of KMnO4 = 0.165mole

Conc. In mol/L = mole of solute(KMnO4)/volume of solution

Conc. In mol/L = 0.165mol/0.35

conc. in mol/L = 0.471mol/L