The following precautions should be observed: where the burette is not closed by a cork, let a few drops out first to wash away crystals of silver nitrate which may have formed at the mouth.
When filling theburette a glass funnel should be used, so that the cork used for closing the burette is not wetted with the silver solution.
Though some other kinds of burette may be easier to use, that here recommended (that of Gay-Lussac) is the most convenient for reasons into which we need not enter.
A graduated burette (each division of which equals a grain-measure of water) is next filled with the solution (No.
A single drop is let fall from a burette or glass rod held steadily above the water, upon the centre of the surface.
Fill a burette with the solution of soda, and cautiously drop this into 63 gr.
The number of degrees of the burette are then read off, and indicate the quantity of copper which has been required to produce the reaction.
It is dropped from the burette into the liquid to be tested, until free iodine begins to appear in the solution.
The next step is to fill a burette (which must be graduated to grains) with the diluted urine to 0.
Fill a burette with this solution and drop it cautiously in 1000 grain-measures of the volumetric solution of iodine until the brown colour is just discharged.
He pours in the copper solution drop by drop by means of a burette graduated into tenths of a c.
After this, water is poured into the funnel, t, and the burette is put in communication with the gas reservoir by means of a rubber tube.
The gas in the burette is first mixed with atmospheric air, by allowing the liquid to flow through b, and causing air to enter through the axial aperture of the three way cock, a, after cutting off communication at v.
While the water is flowing through b, the burette becomes filled with gas.
The combustion is effected by causing the mixture of gas to pass from the burette into the tube, B, through the tube, v, heated to redness, into which there passes a palladium wire.
The absorbing liquid (caustic potassa or pyrogallate of potassa) is poured into a porcelain capsule, P, and the point of the burette is dipped into the liquid.
In order to hasten the absorption, the cock, b, is closed, and the burette is shaken horizontally, the aperture of the funnel being closed by the hand during the operation.
Then the latter is opened, as is also the pinch cock on the rubber tubing, and water is allowed to enter the burette through the bottom until the level is at the zero of the graduation.
For analyzing the gases of blast-furnaces the various apparatus of Orsat have long been employed; but, by reason of its simplicity, the burette devised by Dr.
The lower point of the burette is put in communication with a rubber pump, V (Fig.
The water is allowed to rise into the burette as far as the cock, and the cocks, b and b¹, are afterward closed.
Mother Burette would give at least five hundred francs for the lot," said the widow, after closely examining each article.
Orsat Apparatus] Before taking a final sample for analysis, the burette A should be filled with gas and emptied once or twice, to make sure that all the apparatus is filled with the new gas.
The burette A is graduated in cubic centimeters up to 100, and is surrounded by a water jacket to prevent any change in temperature from affecting the density of the gas being analyzed.
The gas is drawn into the burette to a point below the zero mark, the cock G then being opened to the air and the excess gas expelled until the level of the water in F and in A are at the zero mark.
Their percentage by volume can then be correctly read on the burette divisions, and the percentage by weight calculated from the specific gravities.
The gas is drawn into the burette through the U-tube H, which is filled with spun glass, or similar material, to clean the gas.
To discharge any air or gas in the apparatus, the cock G is opened to the air and the bottle F is raised until the water in the burette reaches the 100 cubic centimeters mark.
But if the poison has been discovered, the solution reserved in the burette should be evaporated, dissolved in water and a little dilute acid, avoiding heat, and titrated by Mayer’s reagent to ascertain the quantity.
Ordinary burette size will perhaps be the most suitable for routine work; the tube is furnished with a stopcock and is bent at B, the tube at K having a very small but not quite capillary bore.
The bromine-water is now run into the bottle containing the standard solution of carbolic acid from a burette until there is no further precipitate; the bottle is stoppered and shaken after every addition.
To fill the apparatus with the soda solution, the gas burette is put on the indiarubber stopper of basin W, and firmly clamped down.
When the burette is filled with soda solution half-way up the funnel Y, A and C are closed, and B opened.
The burette is again put hermetically on the indiarubber stopper in basin W, and the apparatus is left to cool until the water discharged through P shows the same temperature as the water flowing through (into the cooling jacket) Z.
If the level of the soda solution in the tube X is now put on exactly the same level as that in the burette by lowering or elevating the tube X as required, the volume of NO obtained in c.
Mother Burette is as great a brute in her way as her lover, M.
Mother Burette has no other way of living besides the two you have named, I suppose?
I verily believe Mother Burette has dealings with the old one, and practises magic in this private apartment; leastways, that is what M.
She now lies in a dying state; they have had nothing for all that period besides Louise's wages and what they could obtain from Mother Buretteupon the few wretched articles they could dispose of.
Now suppose: Some one brings Mother Burette a shirt worth three francs; well, she lends ten sous upon condition of being paid twenty at the end of the week, otherwise she keeps the shirt for ever.
However, by this threat Mother Burette received her twenty francs at the end of seven days, and Madame Herbelot got back her disagreeable, screaming parrot.
Burette will give at least five hundred francs for the whole," said the widow, after a close examination.
Madame Burette knew the housekeeper of the notary; she gave me a letter to her, in which she strongly recommended Louise.
I shall be soft enough this time again to do just as Burette wishes, and Micou also; but he is a friend.
But if all these stories are believed, why do they not pay Mother Burette and myself a visit?
In the experiments where a burette is used for measuring reagents, the burette is first filled with the reagent by means of a funnel.
From theburette run in N/10 KOH solution until a faint pink tinge remains permanently.
The capacity of a flour to absorb water is determined by adding water from a burette to a weighed amount of flour until a dough of standard consistency is obtained.
The tip of the burette is allowed to fill before the readings are made, which are from the lowest point or meniscus.
Run in standard KOH solution from a burette until a faint pink tinge remains permanently.
If you hold a burette partly filled with water between the eye and a strongly illumined wall, the surface of the fluid presents the appearance shown in fig.
The actual height of the fluid in the burette is of no consequence, since, if the operation be commenced with the line on the float opposite the 0 gradation on the burette, the same proportional division is always maintained.
Another condition is, that when the float has been pressed down in the fluid of the closed burette it should slowly rise again.
In volumetric analysis the method of taking the readings of the burette is an operation of great importance, requiring considerable method and practice.
The first burettewas invented by Gay-Lussac, a drawing of whose instrument is given below.
The float has a circular mark scratched by a diamond, running round the middle, which, when the instrument is placed in the fluid in the burette, should correspond with the graduation or degree on the burette at which the fluid stands.
A weak solution of permanganate is then run in from a burette with a glass cock, the flask being shaken after the addition of every 10 c.
This solution is added by means of a burette to the solution of chloride of lime intended to be tested (10 grams of the sample to 1 litre) the completion of the reaction being known by the paper remaining uncoloured.
To test the correctness of the graduation of a burette proceed as follows:--Fill the instrument up to the highest division with water at 60.
And subsequently when the burette is used, the volumes read from the scale on the burette must be corrected.
A burettemay be calibrated by filling it with distilled water, drawing off portions, say of 5 c.
Suppose, for example, that a burette delivered the following weights of water from each division of 5 c.
When, however, a pipette orburette has to be calibrated to deliver a certain volume of water, the final calibration must be made with this liquid.
The burette is now filled with a solution of potassium bichromate and sulphuric acid and allowed to soak for some time; the bichromate is washed out and distilled water is put in.
Thus, the burette would first be calibrated by weighing in definite quantities of mercury of say 13.
If burettes are wanting, and one must be used for several samples, a Mohr's burette with glass cock is the most convenient to use.
Pour acidulated water into the mouth of the burette till the water in the U tube is about one-half inch from the top.
The level in the burette does not necessarily have to correspond with the zero graduation, but must not be below it.
The water level in the U tube and burette should now be the same, or further adjustment must be made to attain this result.
Adjust so that the zero position of the buretteis about one-half inch below the level of the top of the U tube.
The burette consists of two hollow tubes of glass.
Do not remove the drop on the point of the burette with the test-rod; let it remain where it is or drop it into the solution by carefully opening the clip.
Fill a burette having a glass stop-cock with the iodine solution, and run it into the solution of arsenic, rapidly at first, and then more cautiously, till a final drop produces a blue colour throughout the solution.
The standard solution must be put in a burette with a glass stopcock, as it attacks india-rubber.
Tint with methyl orange, and run in from an ordinary burette normal solution of sulphuric acid until a pink tint is got.
A convenient plan for filling a burette from below is shown in fig.
Fill an ordinary burette with the weaker standard salt solution, and run 1 c.
On running the solution from the burette into the assay, do not let it run down the side of the flask.
The titration in the presence of zinc is comparatively easy, but, in learning it, it is well to have a burette with cyanide so that if a titration be overdone it can be brought back by the addition of 1 or 2 c.
Fill an ordinary burette with the uranium acetate solution, and run into the assay a quantity known to be insufficient.
The standard solution of silver nitrate is placed in a burette divided into tenths of a c.
When using a burette, the water must be run out; the burette is next rinsed with some of the solution to be used, and drained; and then it is filled with the solution.
Next, the amount added is read off from the burette, still more is poured in until the colour is slightly darker than that of the assay, and the burette read off again.
Run in the standard solution from a burette speedily, until the re-agent appears to have a slower action, and shake or stir all the time.
The bottle containing the standard solution is connected with the burette by a syphon arrangement through the glass tube and T-piece.
The burette is connected by a rubber tube and a Y-piece, either with anotherburette or with a piece of ordinary combustion-tube of about the same size.
The silver solution is then run in from the burette (with constant shaking of the flask), a little at a time but somewhat rapidly, until a permanent turbidity appears.
If a fifth normal caustic solution is used, the reading on the burette gives the percentage of free fatty acid directly.
In order to calculate the percentage of free fatty acid as oleic acid, multiply the number of cubic centimeters of tenth normal alkali used as read on the burette by 0.
Hold the paper about two small divisions below the meniscus and raise or lower the level of the eyes until the edge of the paper at the back of the burette is just hidden from the eye by that in front (Note 2).
Add two drops of phenolphthalein solution, and run in alkali from the burette until the solution is pink; add acid from the other burette until the pink is just destroyed, and then add 0.
It is best to wash out a burette at least three times with small portions of a solution, allowing each to run out through the tip before assuming that the burette is in a condition to be filled and used.
Similarly, a buretteused for the titration of the 50 cc.
Fill a glass-stoppered burette with the permanganate solution, observing the usual precautions, and fill a second burette with the ferrous sulphate solution prepared for use with the potassium bichromate.
This can best be done as follows: Wrap around the burette a piece of colored paper, the straight, smooth edges of which are held evenly together with the colored side next to the burette (Note 1).
It is preferable to use a plain burette for this solution.
From the records of calibration already obtained, correct the burette readings and make corrections for temperature, if necessary.
Run in the arsenite solution from a burette until no further reaction takes place on the starch-iodide paper when touched by a drop of the solution of bleaching powder.
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 above list will hopefully give you a few useful examples demonstrating the appropriate usage of "burette" in a variety of sentences. We hope that you will now be able to make sentences using this word.
