7. Sodium nitrite was assayed by residual titration with 0.1N potassium permanganate and 0.1 N oxalic acid. What is the gram-equivalent weight (gew) of sodium nitrite? (NaNO2=68.99g/mol) NaNO2+ KMnO4 +H2SO4 ® HNO3 + MnSO4 + Na2SO4 + K2SO4 + H2O KMnO4 + H2C2O4 + H2SO4 ® MnSO4 + K2SO4 + CO2 + H2O ㅋ

A 0.1093-g sample of impure Na2CO3 was analyzed by the Volhard Method. After adding 50.00 mL of 0.06911 M AgNO3, the sample was back titrated with 0.05781 M KSCN, requiring 27.36 mL to reach the end point. Report the purity of Na2CO3sample.

1. What is the molar solubility of PbCl2 in a solution of 0.23 M CaCl2? Ksp = 1.6 ✕ 10-5 for PbCl2.   2. What is the Qsp when 32.0 mL of 6.50 ✕ 10-7 M Na3PO4 are mixed with 41.4 mL of 5.50 ✕ 10-5 M CaCl2? Assume the volumes are additive. Ksp = 2.0 ✕ 10-29.   3. What is the Qsp when 61.0 mL of 1.50 ✕ 10-4 M AgNO3 are mixed with 80.0 mL of 5.20 ✕ 10-3 M CaCl2? Assume the volumes are additive. Ksp = 1.6 ✕ 10-10.   4. What [I-1] is needed to start the precipitation of AgI from a saturated solution of AgCl? Ksp = 2.9 ✕ 10-16 for AgI and Ksp = 1.2 ✕ 10-10 for AgCl.

When standardizing two liters of a potassium permanganate solution with a primary standard solution of sodium oxalate, approximately 0.0100 M, it was planned to use between 30.00 mL and 45.00 mL of the titrated reagent. In which mass range (in grams) the primary standard should be weighed? Data: MM KMnO4 = 158.00 g/mol; MM Na2C2O4 = 134.00 g/mol 2CO2 + 2e- ↔ C2O4 2-     Eo = -0,432 V MnO4 - + 8 H+ + 5e- ↔ Mn2+ + 4 H2O  Eo = 1,52 V

A 0.1093-g sample of impure Na2CO3 was analyzed by the Volhard Method. After adding 50.00 mL of 0.06911 M AgNO3, the sample was back titrated with 0.05781 M KSCN, requiring 27.36 mL to reach the end point. Report the purity of Na2CO3 sample.

Which of the following experiments can be described as a displacement titration?   A.  Calcium in powdered milk is determined by dry ashing a 1.50 g sample and then titrating the calcium with 12.1 mL of 0.008949 M EDTA.   B.  The Tl in a 9.57-g sample of rodenticide was oxidized to the trivalent state and treated with an unmeasured excess of Mg/EDTA solution. The reaction is Tl3+ + MgY2- -> TlY- + Mg2+   Titration of the liberated Mg2+ required 12.77 mL of 0.03610 M EDTA.   C.  A 3.650-g sample containing bromide was dissolved in sufficient water to give 250.0 mL. After acidification, silver nitrate was introduced to a 25.00-mL aliquot to precipitate AgBr, which was filtered, washed, and then redissolved in an ammoniacal solution of potassium tetracyanonickelate(II): Ni(CN)42- + 2AgBr(s) -> 2Ag(CN)2- + Ni2+ + 2Br-   The liberated nickel ion required 26.73 mL of 0.02089 M EDTA.   D.  A solution contains 1.569 mg of CoSO4 (155.0 g/ mol) per milliliter. 50.00 mL of 0.007840 M EDTA…

The Kjedahl procedure was used to analyze 256 µL of a solution containing 37.0 mg protein/mL. The liberated NH3 was collected in 5.00 mL of 0.033 6 M HCl, and the remaining acid required 6.34 mL of 0.010 M NaOH for complete titration. What is the weight percent of nitrogen in the protein?  wt%

How much amount (in grams) do you need to prepare the following solutions 500.0 mL 0.1000 M stock EDTA solution from Na2H2EDTA•2H2O (FW=372.24) and MgCl2•6H2O crystals 100.0 mL 0.0500 M stock Ca2+ solution from pure CaCO3 (FW=100.09) and concentrated HCl 250 mL 1.0 M NH3-NH4+ pH 10 buffer solution from NH4Cl and NH3

In how much volume of diluted sulfuric acid should you dissolve a multivitamin tablet of approximately 1700 mg of Vitamin C to back analyze 10.00 mL of that solution, with 25.00 mL of 0.01 M KIO3 and 0.04 M thiosulfate to use approximately 8-10 mL of titrant ? You have 25, 50, 150, 250 and 500 mL flasks.

What is the mass of pure dry CaCO3 (MW: 100.0869 g/mol) standard used in the standardization of EDTA solution? Assume that 1.758 M EDTA solution was computed based on the titration of CaCO3 standard. The volume of titrant needed to reach the endpoint was 35.00 mL.   Ca2+ + Y4- →  CaY2-         0.1500 g                       5.630 g     6.158 g                                     0.6158 g