Question

Please help me double-check my answer: Calculate the molarity of an aqueous solution that contains 36.5g KMnO4 and has a total volume of 375 mL.
My answer is 0.616M but this option is not offered.

Answer 1

Answer:

Molarity = 0.616 M

Explanation:

Step 1: Data given

Mass of KMnO4 = 36.5 grams

Molar mass of KMnO4 =  158.03 g/mol

Volume of the solution = 375 mL = 0.375 L

Step 2: Calculate moles KMNO4

Moles KMnO4 = mass KMnO4 / molar mass KMnO4

Moles KMnO4 = 36.5 grams / 158.03 g/mol

Moles KMnO4 = 0.231 moles

Step 3: Calculate molarity of the aqueous solution

Molarity = moles / volume

Molarity = 0.231 moles / 0.375 L

Molarity = 0.616 M

The molarity is 0.616 M, your answer is correct. It must be an error in the options given.

Answer 2

Answer:

The answer to your question is Molarity = 0.6158, I got the same answer as you.

Explanation:

Data

Molarity = ?

Mass of KMnO₄ = 36.5 g

Total volume = 375 ml

Process

1.- Calculate the Molar mass of KMnO₄

KMnO₄ = (1 x 39.10) + (54.94 x 1) + (16 x 4)

            = 39.10 + 54.94 + 64

            = 158.04 g

2.- Calculate the moles of KMnO₄

                158.04 g of KMnO₄ ------------------- 1 mol

                  36.5 g of KMnO₄ ---------------------  x

                   x = (36.5 x 1) / 158.04

                   x = 0.231 mol

3.- Convert the volume to liters

                  1000 ml -------------------- 1 L

                    375 ml --------------------- x

                     x = (375 x 1)/1000

                    x = 0.375 L

4.- Calculate the Molarity

Molarity = moles / volume

-Substitution

Molarity = 0.231 moles / 0.375 L

Result

Molarity = 0.6158