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There was a rustle of branches, and a negro colossus, of the low-browed, heavy-jawed type, plunged through the thicket and barred the path. Bareheaded, barefooted, his shirt consisting of a piece of cloth with holes for head and arms, his trousers torn to tatters by thorns, the warder of the Citadel looked what he was, a Caco machete man, little removed from the ferocity of African savagery.
Calcium oxalate is nearly insoluble in water, and only very slightly soluble in acetic acid, but is readily dissolved by the strong mineral acids. The reactions involved are CaC O > CaCO + CO, CaCO + H SO > CaSO + H O + CO . Dilute the solution cautiously until the salts are brought into solution, adding a little acid if the solution has evaporated to very small volume.
!Answer!: 1.152 grams. What weight of cream of tartar must have been taken for analysis in order to have obtained 97.60% KHC H O in an analysis involving the following data: NaOH used = 30.06 cc.; H SO solution used = 0.50 cc.; 1 cc. H SO sol. = 0.0255 gram CaCO ; 1 cc. H SO sol. = 1.02 cc. NaOH sol.? !Answer!: 2.846 grams.
The ignited product is assumed to be CaO and the analyst reports 29.50% Ca in the sample. Owing to insufficient ignition, the product actually contained 8% of its weight of CaCO . What is the correct percentage of calcium in the sample, and what is the percentage error? !Answers!: 28.46%; 3.65% error. !Answer!: 0.2359 gram. What fraction of this volume of acid is used for oxidation?
So now remember that chalk is carbonate of lime, and that it is made up of three things, calcium, oxygen, and carbon; and that therefore its mark is CaCO , in Analysis's language, which I hope you will be able to read some day. But how is it that Analysis and Synthesis cannot take all this chalk to pieces, and put it together again? Look here; what is that in the chalk?
A limestone is found to contain 93.05% CaCO , and 5.16 % MgCO . Calculate the weight of CaO obtainable from 3 tons of the limestone, assuming complete conversion to oxide. What weight of Mg P O could be obtained from a 3-gram sample of the limestone? !Answers!: 1.565 tons; 0.2044 gram. A sample of dolomite is analyzed for calcium by precipitating as the oxalate and igniting the precipitate.
He thrust aside, as unimportant, the machete of the Caco who threatened him, and the assumption of authority took the guerilla aback. Quietly, and with perfect coolness, he walked up to the Haitian general. A little to Stuart's surprise, he spoke the Haitian dialect perfectly. "You're goin' to untie de ropes 'round dat boy, Yes!" he declared, "an' if you're wise, you do it quick.
A solution of sulphuric acid is standardized against a sample of calcium carbonate which has been previously accurately analyzed and found to contain 92.44% CaCO and no other basic material. Calculate the normal value of each. !Answers!: Acid 0.4398 N; alkali 0.4409 N. !Answer!: 0.7084 N.
The fire so kindled was called caco fuech. According to the latter writer, in Saintonge it was the mistress of the house who blessed the Yule log, sprinkling salt and holy water on it; in Poitou it was the eldest male who officiated. The log was called the cosse de Nô. The author speaks of the custom as still practised in out-of-the-way villages at the time when he wrote. See above, p. 251.
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