The phosphate in a 3.00 g sample of industrial detergent was precipitated by the addition of 1.000 g of AgNO₃ (169.87 g/mol). The solution was filtered and the filtrate, upon addition of 1.00 mL of 0.01 M FeCl₃, required 18.23 mL of 0.1377 M KSCN for titration to the endpoint. Identify (a) what type of precipitation titrimetry was used (b) which served as the indicator (c) the color at the end point Calculate (d) the weight percent of phosphate (94.97 g/mol) in the detergent.

The phosphate in a 3.00 g sample of industrial detergent was precipitated by the addition of 1.000 g of AgNO₃ (169.87 g/mol). The solution was filtered and the filtrate, upon addition of 1.00 mL of 0.01 M FeCl₃, required 18.23 mL of 0.1377 M KSCN for titration to the endpoint. Identify (a) what type of precipitation titrimetry was used (b) which served as the indicator (c) the color at the end point Calculate (d) the weight percent of phosphate (94.97 g/mol) in the detergent.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter17: Complexation And Precipitation Reactions And Titrations

Section: Chapter Questions

Problem 17.34QAP

See similar textbooks

Similar questions

A volume of 50 mL of 1.8 M NH3 is mixed with an equal volume of a solution containing 0.95 g of MgCl2. What mass of NH4Cl must be added to the resulting solution to prevent the precipitation of Mg(OH)2?
Iron (55.845 g/mol) can be determined gravimetrically by precipitation as Fe(OH)3 (106.867 g/mol) and subsequent inflammation of the precipitate to convert it to Fe2O3 (159.69 g/mol). A 0.7873 g sample to be analyzed was weighed and transferred to a 400 mL beaker, where it was dissolved in 50 mL of H2O and 10 mL of 6M HCl. Then 2 mL of concentrated HNO3 was added to the solution. After boiling to remove excess HNO3 and nitrogen oxides, the solution was diluted to 200 mL, brought to boiling, and Fe(OH)3 was precipitated by the slow addition of 1:1 NH4OH solution until an odor of NH3 was detected (indicating the presence of excess NH3 in the medium). The solution was left in a water bath at 80 ºC for 30 min at rest. The precipitate was then filtered and washed with several portions of hot 1% m/v NH4NO3 until no Cl– was detected in the wash water. Finally, the precipitate was ignited at 500-550 °C, then left in a desiccator to cool and weighed as Fe2O3, resulting in a mass of 0.4512 g.…
A saturated solution of magnesium hydroxide is prepared and the excess solid magneisum hydorixed is allowed to settle. A 25.0 mL aliquot of the saturated solution is withdrawn and transfered to a flask, two drops of inficator are added. A 0.00053 M HCL is dispensed from a buret into a solution. The solution changes color after the addition of 13.2 mL. What is the solubility product, Ksp, for magensium hydroxide?
Limestone consists mainly of the mineral calcite, CaCO 3. The carbonate content of 0.5413 g of powdered limestone was measured by suspending the powder in water, adding 10.00 mL of 1.396 M HCl, and heating to dissolve the solid and expel CO 2: CaCO 3(s) + 2 HCl → CaCl 2 + CO 2(g) + H 2O The excess acid required 39.96 mL of 0.1004 M NaOH for complete titration to a phenolphthalein end point. Find the weight percent of calcite in the limestone.
Limestone consists mainly of the mineral calcite, CaCO3. The carbonate content of 0.5413 g of powdered limestone was measured by suspending the powder in water, adding 10.00 mL of 1.396 M HCl, and heating to dissolve the solid and expel CO2: CaCO3(s, 100.087 g/mol) + 2 H+ → Ca2+ + CO2(g) + H2O The excess acid required 39.96 mL of 0.1004 M NaOH for complete titration to a phenolphthalein end point. Find the weight percent of calcite in the limestone.
1.0 g of a solid sample known to contain a mixture of NaOH and Na2CO3 is dissolved with distilled water and completed to 25 mL. By adding 2 drops of phenolphthalein (pT = 9.0) to the solution obtained, it was titrated with 0.107 M calibrated HCl solution, and the consumption was determined as 10.6 mL. Subsequently, 2 drops of methyl red (pT = 4.4) were added onto the same solution and titrated, the consumption was determined as 6.1 mL. Accordingly, calculate the amount of NaOH and Na2CO3 in the sample solution as% (a/a) by writing the related reactions. (Na: 23, C: 12, O: 16, H: 1 g / mol)
1.00 grams of table salt was dissolved in 100 mL water and excess AgNO3 reagent was added and yielded 2.3789 grams of precipitate. Calculate the percentage of NaCl in the table salt.
Identify the type of coprecipitation that occurred in the following situation. (a) The precipitation of bulky precipitates (e.g. MgNH4PO4) traps significant amount of the solution in the crystalline precipitate. ____________ (b) The formation of equimolar replacement (Al, Fe) 203 during the precipitation of hydroxides in a solution containing A13+ and Fe3+ _____________ (c) The coprecipitation of soluble ions (e.g. Na+ and CI) in the solution because of the absorption of electrolytes by colloidal precipitates. _____________ (d.) Dust particles may coprecipitate as crystals grow on the surface of the dust particles. ___________ (e.) lons in the solution may be trapped inside the precipitate during the crystal growth process.___________ Fill in the blanks with the following choices: occlusion, mechanical entrapment, surface absorption, mixed crystal formation
An acidic solution of copper (.35 M Cu+2) was treated with KOH until Cu(OH)2 precipitated. At what pH does this occur at?
A weighed sample of sodium nitrite was treated with 0.05 mol of ceric sulfate in solution, in air-free conditions. The resulting solution was titrated with standard Fe(II) solution and 0.01 mol of Fe(II) were required. Determine the moles of sodium nitrite present in the weighed sample. NO2– + 2 Ce4+ + H2O → NO3– + 2 Ce3+ + 2 H+ Fe2+ + Ce4+→ Fe3+ + Ce3+
If a sample of silver coin weighing 0.5230 g gives a precipitate of AgCl (143.45) weighing 0.3559 g, the weight of AgBr (187.90) that could have been obtained from the same weight of sample is 0.89 grams. true or false?
a.) What is the precipitation pH in gravimetric sulfate determination? Why is precipitation not done in a strongly acidic medium? What inconvenience does it cause if the heating process is over 800 °C?b.) What is the K2SO4 content of a sample that gives 0.699 g of precipitate in HCl with BaCl2 solution? (BaSO4: 233; K2SO4: 175).