Question
Stocksolution of KMnO4= 0.004029 M
2. Obtain 5 clean, dry 100-mlvolumetric flasks. Pour approximately 50 ml of the stocksolution in a beaker. Pipet exactly 1.00, 2.00, 4.00, 6.00and 8.00 ml of the stock solution in individual 100-ml volumetricflasks.
3. Add 10 ml of 3.0 M sulfuric acidmeasured with a graduated cylinder to each of the flasks.
4. Bring the volume to the mark withdistilled water in each of the flasks.
5. Calculate the molarity of each ofthe standard solutions that you made in the above steps.
I understanddilutions are M1V1=M2V2but does the H2SO4 make a difference in doingthe equation or no?
Explanation / Answer
Molarity of the stock solution of KMnO4 = 0.004029M In the first dilution, 1.00 mL of the stock solution isdiluted to 100 mL Then the molarity of the resulting solution will be, M1V1 = M2V2 0.004029 M * 1.00 mL = M2 * 100 mL M2 = 0.00004029 M In the second dilution, 2.00 mL of the stock solution isdiluted to 100 mL 0.004029 M * 2.00 mL = M2 * 100 mL M2 = 0.00008058 M In the third dilution, 3.00 mL of the stocksolution is diluted to 100 mL 0.004029 M * 3.00 mL = M2 * 100 mL M2 = 0.00012087 M In the fourth dilution, 4.00 mL of the stocksolution is diluted to 100 mL 0.004029 M * 4.00 mL = M2 * 100mL M2 = 0.00016116 M The dilutions can be calculated likewise. The addition of H2SO4 has nosignificant effect on the concentrations of the solution, it isadded to make the solution of potassium permanganate acidicrendering it a capacity to be used as a self indicator in a redoxtitration. 0.004029 M * 1.00 mL = M2 * 100 mL M2 = 0.00004029 M In the second dilution, 2.00 mL of the stock solution isdiluted to 100 mL 0.004029 M * 2.00 mL = M2 * 100 mL M2 = 0.00008058 M In the third dilution, 3.00 mL of the stocksolution is diluted to 100 mL 0.004029 M * 3.00 mL = M2 * 100 mL M2 = 0.00012087 M In the fourth dilution, 4.00 mL of the stocksolution is diluted to 100 mL 0.004029 M * 4.00 mL = M2 * 100mL M2 = 0.00016116 M The dilutions can be calculated likewise. The addition of H2SO4 has nosignificant effect on the concentrations of the solution, it isadded to make the solution of potassium permanganate acidicrendering it a capacity to be used as a self indicator in a redoxtitration.