KMnO4 and Na2C2O4 solutions were used in the reactions that took place in a back titration to determine the amount of H2O2 in a sample. Calculate the concentration of H2O2 in the sample (w / v) as% by making appropriate assumptions for the volumes and normality of all these solutions.

A 10.0 g piece of pure aluminum is placed in 75.0 mL of 0.54 M hydrochloric acid at STP condition. They react as follows:2Al +  6HCl  →  3H2(g)  +  2AlCl3 Calculate the following: Volume, in liters, of hydrogen gas.  Molarity of Al+3. (Assume 75.0 mL solution.) Molarity of Cl. (Assume 75.0 mL solution.)

A newly-discovered iron ore was examined to determine percent iron in the ore gravimetrically. 5.408 grams of the ore samples was subjected to gravimetric analysis and precipitated as iron (III) oxide and dried at 105 degrees Celsius. What is the percent iron contentn of the ore if the mass of the precipitate is 0.3785 grams?

The hydrogen sulfide in a 75.0-g sample of crude petroleum was removed by distillation and uncollected in a solution of CdCl2. The precipitated CdS was then filtered, washed, and ignited to CdSO4. Calculate the percentage of H₂S in the sample if 0.115 g of CdSO4 was recovered.

When standardizing two liters of a potassium permanganate solution, approximately 0.0100 M, with a primary standard solution of sodium oxalate, it was planned to use between 30.00 and 45.00 ml of the titrated reagent. In which mass range (in grams) the primary standard should be weighed?

2. The reaction between lead(II) nitrate and potassium iodide solution is shown below   Pb(NO3)2(aq) + 2 KI(aq) → 2 KNO3(aq) + PbI2   Calculate the mass of lead(II) iodide precipitated when 5.00 cm3 of 4.00 mol dm–3 lead(II) nitrate solution  is mixed with 7.50 cm3 of 5.00 mol dm–3 potassium iodide solution.    [Mr / g mol–1: PbI2 = 461.01]

13. Hydroxyapatite is the main mineral component of bone. How many grams of hydroxyapatite will dissolve in 1.00 L of H20? Ksp = 2.34 x 10-59; Molar mass = 502.3 g/mol Cas (PO4)30H (s) 5 Ca2+ (aq) + 3 PO43- (aq) + OH- (aq)

The gravimetric determination of Ni: Ni (58.7 g/mol) was precipitated as Ni(DMG) 2 (288.7 g/mol). The volume of unknown solution in the sample =30.00 mL. The mass of empty crucible = 30.107 g, the mass of empty crucible and precipitate = 30.300 g. Calculate the concentration of NiT in the unknown in sample solution (in mg/L) is: 1. O2.62X103 2. O1.31X 103 3. 25.3X 104 4. 00.5X 10 Previous Next hp

The Kjeldahl method was used to determine the nitrogen content of a protein. A 275 µL aliquot of a 47.0 mg/mL protein solution was digested in boiling sulfuric acid. The solution was made basic and the liberated NH, was collected in 5.00 mL of 0.0512 M HCl. A volume of 7.00 mL of 0.0174 M NaOH was required to react with the excess HCl. Calculate the weight percent of nitrogen in the protein. weight percent: wt% N

Q/ Mohr's method uses the potassium chromate indicator and this indicator makes the equivalent point not identical to the end point. A sample weighing 5.592 g of BaCl2 is dissolved in 500 mL of water. Calculate the percentage of chloride in the sample when 25 mL of the sample is titrated and requires 33.47 mL of 0.1098 N AGNO. SOLUTION: