Question

2. In order to analyze a commercial H O solution using the procedure in this experiment, it must first be diluted with distilled water. Consider 10.0 mL of a commercial peroxide solution measured with volumetric pipet diluted to 100.0 mL in a volumetric flask. If 25.00 mL of the diluted solution is titrated with 0.0202 M MnO4, calculate the percent H2O2 in the commercial peroxide solution, i.e. before dilution. The initial buret reading was 0.08 mL, and the final reading was 27.59 mL. Assume that the diluted peroxide solution had a density of 1.00 g/mL.

Answer 1

Balameed redox reaction between Mm04 & HzOz is 2Mm0q+6H++5 H2Oz 2 Mm" t 8 HzO +502 Requived Mmo4 (27-59 -0 08) 27.51 m2 2 mol Mm0g = ml H202 1000 ml 2 (M) Mmo4 = 5 mol 02 2751 m 0.0202 (M) mmog = 5 x0.0202X27.3l H202 1000 - 139 x 10 mol H02 25 ml stock mlution centain l:3x 10 mol 02 1.39X 10 1oo0 mL 100 25 ta5 5.56 2 X10 mol Henee 10 ml commereial 02 silution (before dilution) 5.56 contain Moleenlar weight of th02 = 34 /mol 25.5 -3 mol 202 = density of peroxide melution=19/mL {8=M 10 ml roltion 1og wltia %3D rolution eentain O 19 batae g 202 .10 100 g The commerial H202 luthon contain 1.9% (W/W)Ho,