A mixture containing only Al2O3 (FM 101.96) and Fe2O3 (FM 159.69) weighs 2.019 g. When heated under a stream of H2, the Al2O3 is unchanged, but the Fe2O3is converted to metallic Fe plus H2O(g). If the residue weighs 1.774 g, what is the weight percent of Al2O3 in the original mixture?

A mixture containing only Al2O3 (FM 101.96) and Fe2O3 (FM 159.69) weighs 2.019 g. When heated under a stream of H2, the Al2O3 is unchanged, but the Fe2O3is converted to metallic Fe plus H2O(g). If the residue weighs 1.774 g, what is the weight percent of Al2O3 in the original mixture?

Chemistry & Chemical Reactivity

10th Edition

ISBN:9781337399074

Author:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Publisher:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Chapter21: The Chemistry Of The Main Group Elements

Section: Chapter Questions

Problem 97GQ

See similar textbooks

Similar questions

2. An iron ore was analyzed by dissolving a 1.1324 g sample in concentrated HC. The resulting solution was diluted with water, and the iron(III) was precipitated as hydrous oxide Fe,03 .XH20 by the addition of NH3. After filtration and washing, the residue was ignited at a high temperature to give 0.5394 g of pure Fe,03 (FW = 159.69). Calculate (a) the percent Fe (FW = 55.847) and (b) the percent Fe;04 (FW = 231.54) in the sample.
A solution of I3- was standardized by titrating freshly dissolved arsenious oxide (As4O6, FM 395.683). The titration of 25.00 mL of a solution prepared by dissolving 0.3663 g of As4O6 in a volume of 100.0 mL required 31.77 mL of I3-. Calculate the molarity of the I3- solution.
A solution of I3- was standardized by titrating freshly dissolved arsenious oxide (As4O6, FM 395.683). The titration of 25.00 mL of a solution prepared by dissolving 0.3663 g of As4O6 in a volume of 100.0 mL required 31.77 mL of I3-. Calculate the molarity of the I3- solution. As4O6(s) + 6H2O ⇌ 4H3AsO3 H3AsO3 + I3- + H2O ⇌ H3AsO4 + 3I- + 2H+ a. 0.01657 M b. 0.02914 M c. 0.1166 M d. 0.0957 M
1. A student synthesized 3.214g of Ni(NH3)„Cl2 from 4.023g of N¡C12•6H2O. He dissolved 0.81g of Ni(NH3)nCl2 in 40 mL of 1.0M HCI to make a sample for analysis. Molar mass: Ni 58.7; Cl2 71; NH3 1T; H2O 18. (1) A 0.20M Ni²* standard solution had an absorbance of 1.666, while his sample had an absorbance of 0.705. Calculate the Ni2+ concentration in his sample and the mass percent of Ni in the product. Note: A = ɛbc. (2) The student used 38.75 mL of 0.498M NaOH to neutralize excess HCl in 40mL of the sample. Calculate the mass percent of NH3 in the product.
A 1.9300 g impure sample of Fe(NH4)2(SO4)2 (FW = 392.14) was dissolved in 75 mL 0.75 M H2SO4 and was titrated with the standard KMnO4 in problem 1. Titration of the sample required 24.00mL while the blank containing 75mL 0.75 M H2SO4 required 0.75 mL of the KMnO4 titrant. Calculate the concentration of Fe(NH4)2(SO4)2 in %w/w in the impure sample.
a) What mass of Fe(NH4)2(SO4)2•2H2O(s) is required to prepare a 500 mL solution containing 100 ppm (m:v) in Fe? b) Using this stock solution, what aliquot must be used to prepare calibration solutions, 100 mL volume, of the following concentrations: 0.100 ppm, 0.500 ppm, 2.00 ppm, 4.00 ppm, and 7.00 ppm.
g. Aluminium in 1.200 g sample of impure ammonium aluminium sulphate was precipitated with aqueous ammonia as the hydrous Al2O3.xH2O. The precipitate was filtered and ignited at 1000 °C to give anhydrous Al2O3 which weighed 0.1798 g. Calculate the percentage of aluminium in the sample (Atomic weight Al= 26.98 g mol-1; Molecular weight Al2O3 = 101.96 g mol-1).
0.1745 g of primary standard Na2C2O4 is used to set a freshly prepared KMnO4 solution and 30.24 mL of KMnO4 solution is spent at the turning point. Since 36.92 mL of this KMnO4 solution is consumed for the determination of iron in 0.5618 g ore sample, calculate the amount of iron in the ore in terms of % iron (III) oxide and % iron (III) chloride. (Fe: 56, K: 39, Mn: 55, O: 16, Na:23, C: 12, Cl: 35.5 g/mol) (Please type answer)
3. Analysis of a mixture consisting of NaOH + Na2CO3 + inert matter gives the following data: 10.00 g. Its aqueous solution is diluted to 250.0 mL and two separate 25.00 mL sample portions are titrated. With one portion, an end point with phenolphthalein is obtained in cold solution, with 44.52 mL of 0.5000 N HCI. The other portion requires 46.53 mL of the acid for an end point with methyl orange. Calculate the percentage composition of the original sample.
Calculate the ionic strength (j) for a) the solution of AlCl3 (0.01 N) + Ca(NO3)2 (0.002 M) (A=0.51) b) the solution of CH3COOH 0.01 M , Ka = 10-5 M (A=0.51)
Fifty food supplement tablets with a total mass of 66.393 g were crushed into powder to analyse the content of FeSO4·7H2O. 2.988 g of the powder were dissolved in HNO3 and heated to convert all the iron to Fe3+. Addition of aqueous NH3 caused quantitative .precipitation of Fe2O3· X H2O, which was ignited to give 0.0640 g of Fe2O3. Determine the average weight of FeSO4·7H2O in each tablet.
7