Please answer the following question. For problems requiring calculations, be su

Question

Please answer the following question. For problems requiring calculations, be sure to SHOW ALL WORK and GIVE ANSWERS WITH THE CORRECT NUMBER OF SIGNIFICANT FIGURES AND UNITS. Full credit will not be given for a correct answer unless all of your work is shown. POINTS WILL BE SUBTRACTED if an answer does not have the correct number of significant figures and units(5 points). 1. Potassium permanganate (KMn04) can be used as a disinfectant. How would you prepare 25.0 L of a solution that is 15.0% KMnO4 by mass if the resulting solution has a density of 1.08 g/mL? What is the molarity of the resulting solution? (Provide detail as to how you would dissolve the salt in the solution).

Explanation / Answer

15.0 % by mass of KMnO4 means,

100 g. of solution has 15.0 g. of KMnO4

From the density,

Volume of 100 g. of solution = Mass / density = 100 / 1.08 = 92.6 mL

So, 92.6 mL of solution has 15.0 g. of KMnO4

Then,

25.0 L or 25000 mL of solution has 15.0 * 25000 / 92.6 = 4049.7 g. of KMnO4

Molar mass of KMnO4 = 158 g/mol

Moles of KMnO4 = mass / molar mass = 4049.7 / 158 = 25.6 mol

Molarity = moles of solute / volume of solution

M = 25.6 / 25.0

M = 1.02 M

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