hich of the following sentence is incorrect: O Reprecipitation can be used to remove coprecipitated impurities O Occlusion is a type of coprecipitation in which a compound is trapped within a pocket formed during crystal growth O Coprecipitation may cause either positive or negative errors O Digestion is a process in which a precipitate is heated in the presence of solution to improve the purity and filterability O In peptization, the size of coagulated colloid increases and becomes stable

hich of the following sentence is incorrect: O Reprecipitation can be used to remove coprecipitated impurities O Occlusion is a type of coprecipitation in which a compound is trapped within a pocket formed during crystal growth O Coprecipitation may cause either positive or negative errors O Digestion is a process in which a precipitate is heated in the presence of solution to improve the purity and filterability O In peptization, the size of coagulated colloid increases and becomes stable

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter7: Statistical Data Treatment And Evaluation

Section: Chapter Questions

Problem 7.10QAP

See similar textbooks

Similar questions

What wt of magnetite should be taken for analysis in order that after converting to a precipitate of Fe2O3.xH2O, the percentage of Fe3O4 in the sample can be found by multiplying the wt in grams of the ignited precipitate (Fe2O3) by 100.
The equilibrium for the vorious proportions of the dissociation of the liquid solutions of amyl ester of dichloroacetic ccid (CHCI,.COOC,H,} into the acid (CHCLCOOH) and amylene (C,H was investigated. The inltial amount tor the CHCI,COOC.H used Is 1 mole. Completethe table below Let b the inltial moles of omylene, V the totdl volume cof mixtures in iters, x. be the number of moles of V. 1.05 0.215 0.455 3.12 .af equibrium ond Kc ester outionum constont n.moles per iter. 2.61 0.401 4.45 0.628 3.54 0.794 0.658 3.44
2. In one gravimetric analysis, the aluminum in a 1.2g sample of impure NHAI(SO4)2 was precipitate as hydrous ALO3.XH2O. The precipitate was filtered and ignited at 1000 °C to give anhydrous Al2O3 which weighed 0.1798g. Calculate the % Al inthe sample. 3. A sample of 0.4500g impure potassium chloride was dissolved in water treated with excess silver nitrate solution. 0.8402 g of silver chloride was precipitated. What is the percentage of potassium chloride in the sample?
6. The mercury in a 0.839 g sample was precipitated with an excess paraperiodic acid, H¿IO, 5Hg + 2H,IO, → Hg;(IO,); + 10H The precipitate was filtered, washed free of precipitating agent, dried and weighed, 0.3408 g being recovered. Calculate the percentage of Hg,Cl, in the sample.
The purpose of digestion process in gravimetric analysis is to: 1. O decrease the particle size of the precipitate 2. O evaporate the solvent 3. O dry the precipitate 4. O coagulate the precipitate
A 4.912-g sample of a petroleum product was burnedin a tube furnace, and the SO2produced was collectedin 3% H2O2.Reaction:SO2(g)+H2O2→H2SO4A 25.00-mL portion of 0.00873 M NaOH was introducedinto the solution of H2SO4, following whichthe excess base was back-titrated with 15.17 mL of0.01102 M HCl. Calculate the sulfur concentrationin the sample in parts per million.
during re-crystallization, it's important to use the in smallest possiblefthe solvent at high temperature to: Select one: O a. have a saturated solution of the compound, so when the solution is colder and precipitation starts, the maximum amount of the compound precipitates of tion O b. better dissolve the sample Oc. none of the statements mentioned is valid O d. complete a certain total weight of the mixture ion the aqueous layer is a liquid vwith water as the solvent
A Sample Containfng mmol of KNOS is "parsed 6.00 x10-2² mmol of vesay ad z.00x102 mmol af ves@y ad 2.00x1o2 though a cation -excharye Column. the Colculate. volume o.02.00 M NaH of needed to titrete the elwate,
on in a 1. 200 Sample was precipi toled as the hdroxide and ignited to Ferm Fez0 (0. 352 1 FW= 159-7 lmal). Fnd %Fe (AW : 55-8 glmal)in the Sample. 4 A 2-560 g of impure CCl, Sample was disselved in water and precipitated wii th excess Na Cou Selution. 1F i.245g CaGOu (FW= 12891ml) was obtained, what is the percentage f Cack (FW= mglmal) in the impure Sample? Cu: A 0-21219 sample of an organic Compound was and the Ce, was burned in a stream of oxygen, and the CO2 was Callected in a solution of BalOH), Caleulate the %C in the Sample if o.co06 g of Ba COg was hamedd (FW Ba CO, = 197.34g mol), (AW C=12 glm)
1. Indicate whether each of the following statements is true (T) or false (F) 1. () Mohr method for chloride volumetric determination uses potassium chromate as an indicator. The medium in which the titration should be conducted must be acidic. 2. () Solubility of precipitates in presence of excess precipitating agent increases. 3. () Colloidal precipitates contain very small particles. There should be expected a great deal of error due to adsorption. 4. () Usually a larger break in a titration curve as the concentration becomes larger. 5. () As compared to redox titrations, acid base titrations have less restrictions on selection of a suitable indicator.
Mo in a 0.2711g sample was precipitated giving 1.1682g of (NH4)2PO4.12 MoO3. Find the percentage Mo , P (at wt = 30.97), N=14,Mo=95.9,H=1,O=16
The concentration of ammonia in a cleaning product was determined by back titration.Firstly, 10.00 cm3 of the cleaning product was pipetted into a large conical flask,containing 250.00cm3 of 0.50 mol/l HCl to give Solution A.Following a period of reaction and shaking, 50.00cm3 of Solution A was removed anddiluted to 250 cm3 with water in a volumetric flask to give Solution B.20 cm3 samples of Solution B were titrated against 0.05 mol/l Na2CO3 solution, givingan average titre of 12.45 cm3. i) Write equations for the reactions that have taken place.ii) Determine the concentration of NH3 in the original cleaning product in mol/l,g/l, ppm, and % w/v.