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!Answer!: 35.89% FeO; 10.03% Al O . A sample of magnesia limestone has the following composition: Silica, 3.00%; ferric oxide and alumina, 0.20%; calcium oxide, 33.10%; magnesium oxide, 20.70%; carbon dioxide, 43.00%. In manufacturing lime from the above the carbon dioxide is reduced to 3.00%. How many cubic centimeters of normal KMnO will be required to determine the calcium oxide volumetrically in a 1 gram sample of the lime?
KMnO = 0.2004 gram Na C O . Calculate the percentage of sulphide sulphur in the sample. !Answer!: 0.050%. What weight of pyrolusite containing 89.21% MnO will oxidize the same amount of oxalic acid as 37.12 cc. of a permanganate solution, of which 1 cc. will liberate 0.0175 gram of I from KI? !Answer!: 0.2493 gram.
Determine the percentage of iron in a sample of limonite from the following data: Sample = 0.5000 gram. KMnO used = 50 cc. 1 cc. KMnO = 0.005317 gram Fe. FeSO used = 6 cc. 1 cc. FeSO = 0.009200 gram FeO. !Answer!: 44.60%. If 1 gram of a silicate yields 0.5000 gram of Fe O and Al O and the iron present requires 25 cc. of 0.2 N KMnO , calculate the percentage of FeO and Al O in the sample.
Sulphide sulphur was determined in a sample of reduced barium sulphate by the evolution method, in which the sulphur was evolved as hydrogen sulphide and was passed into CdCl solution, the acidified precipitate being titrated with iodine and thiosulphate. Sample, 5.076 grams; cc. I = 20.83; cc. Na S O = 12.37; 43.45 cc. Na S O = 43.42 cc. I ; 8.06 cc. KMnO = 44.66 cc. Na S O ; 28.87 cc.
An inspection of these equations shows that 2KMO react with 10FeSO , while K Cr O reacts with 6FeSO . These are not equivalent, but if the first equation is multiplied by 3 and the second by 5 the number of molecules of FeSO is then the same in both, and the number of molecules of KMnO and K Cr O reacting with these 30 molecules become 6 and 5 respectively.
Cover the solution with a watch-glass; allow it to stand until cool, or preferably over night. Filter the solution through a layer of asbestos. In neutral solutions the reduction of the permanganate is less complete, and, under these conditions, two gram-molecular weights of KMnO will furnish only 48 grams of oxygen.
In the analysis of a sample of steel weighing 1.881 grams the phosphorus was precipitated with ammonium molybdate and the yellow precipitate was dissolved, reduced and titrated with KMnO . If the sample contained 0.025 per cent P and 6.01 cc. of KMnO were used, to what oxide was the molybdenum reduced? 1 cc. KMnO = 0.007188 gram Na C O . !Answer!: Mo O . !Answer!: 0.009385 gram.
On account of failure to boil out all the excess SO , 38.60 cubic centimeters of 0.1 N KMnO were required to titrate the solution. What was the error, percentage error, and what weight of sulphur dioxide was in the solution? From the following data, calculate the ratio of the nitric acid as an oxidizing agent to the tetroxalate solution as a reducing agent: 1 cc. HNO = 1.246 cc.
A student standardized a solution of NaOH and one of KMnO against pure KHC O .H C O .2H O and found the former to be 0.07500 N as an alkali and the latter exactly 0.1 N as an oxidizing agent. By coincidence, exactly 47.26 cc. were used in each standardization. Find the ratio of the oxalate used in the NaOH standardization to the oxalate used in the permanganate standardization. !Answer!: 1:1.
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