Question

A chemist prepares a solution of potassium permanganate (KMnO4) by measuring out 3.8 umol of potassium permanganate into a 100 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. Round your answer to 2 significant digits. x 5 ? Explanation Check

Answer 1

The concentration of the potassium permanganate solution is 3.8 x 10⁻⁵ M when rounded to two significant digits.

Step-by-step explanation:

The concentration of a solution is calculated by dividing the number of moles of the solute by the volume of the solution in liters. To calculate the concentration of potassium permanganate (KMnO₄) in the chemist's solution, you need to use the equation:

C = n / V

where C is the molarity (concentration) in moles per liter (mol/L), n is the number of moles of KMnO₄, and V is the volume of the solution in liters.

In this case, the student already has 3.8 μmol (or 3.8 x 10⁻⁶ mol) of KMnO₄ and the total volume is 100 mL, which is equivalent to 0.1 L. Therefore, the molarity (C) of the solution is:

C = 3.8 x 10⁻⁶ mol / 0.1 L = 3.8 x 10⁻⁵ M

Thus, the concentration of the potassium permanganate solution is 3.8 x 10⁻⁵ M, which can be rounded to two significant digits as 3.8 x 10⁻⁵ M.

Answer 2

3,8×10⁻⁵ mol/L of potassium permanganate solution

Step-by-step explanation:

To calculate concentration in mol/L you must convert the 3,8 umol to moles and 100 mL to liters, knowing 1 umol are 1×10⁻⁶mol and 1L are 1000 mL.

3,8 umol × (1×10⁻⁶mol / 1 umol ) = 3,8×10⁻⁶mol of potassium permanganate.

100 mL × ( 1L / 1000 mL) = 0,100 L

Thus, concentration in mol/L is:

3,8×10⁻⁶mol / 0,100 L = 3,8×10⁻⁵ mol/L of potassium permanganate solution

I hope it helps!