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Updated: June 21, 2025
Into this solution is then run, from a burette or graduated tube, a standard solution of an acid, that is, a solution prepared by dissolving a known weight of an acid, say hydrochloric acid, in a known volume of water. The acid is run in gradually until the yellow colour changes to pink, at which point the volume of acid used is noted.
It is also desirable that a sufficient excess of the acid should be present to react with a considerable volume of the permanganate solution during the titration, thus increasing the accuracy of the process. On the other hand, the excess of oxalic acid should not be so large as to react with more of the permanganate solution than is contained in a 50 cc. burette.
Similarly, a burette used for the titration of the 50 cc. of solution removed should be calibrated under the same conditions as the measuring flasks or pipettes employed with it. The student should also keep constantly in mind the fact that all volumetric operations, to be exact, should be carried out as nearly at a constant temperature as is practicable.
In the Rue du Temple, No. 17, lives one Burette, pawnbroker, who is accused of being your private receiver." "What would you have me do, M. Borel? one says so many things, the world is so wicked. Once more I say, I must mix with the greatest number of scoundrels possible.
Fill the burettes with the standard acid and alkali solutions, noting the initial readings of the burettes and temperature of the solutions. Run in acid from the burette, stirring and avoiding loss by effervescence, until the solution has become pink.
Besides, there should be ready three small glasses one filled with tincture of litmus, the second with a solution of 1,369 per ammonia, and the third with the must or wine to be tested; also, a taller glass, or vessel, having its bottom covered with cotton, in which glass the burette, after it has been filled with the solution of ammonia, is to be placed in an upright position until wanted.
The student should observe by trial how a reading is affected when the meniscus is viewed from above or below. The eye soon becomes accustomed to estimating the tenths of the divisions. If the paper is held as directed, two divisions below the meniscus, one whole division is visible to correct the judgment. It is not well to attempt to bring the meniscus exactly to a division mark on the burette.
From the final data, plot the corrections to be applied so that they may be easily read for each cubic centimeter throughout the burette. The total correction at each 10 cc. may also be written on the burette with a diamond, or etching ink, for permanence of record. This slowly unites with the main body of liquid, but requires an appreciable time.
I don't care about it," said Calabash, sharply throwing it back into the case. "It is not on account of the shawl that I speak; I am not mean enough to value a shawl; for one, more or less, old Burette will not change her price; she buys in a lump," said Nicholas. "But instead of saying that you'd take the shawl you might ask if I would give it you.
If the burette has a glass stopcock, this should be removed after the cleaning and wiped, and also the inside of the ground joint. The surface of the stopcock should then be smeared with a thin coating of vaseline and replaced. It should be attached to the burette by means of a wire, or elastic band, to lessen the danger of breakage.
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