Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 14, 2025
From the volume of solution required to react with the bleaching powder, calculate the percentage of available chlorine in the latter, assuming the titration reaction to be that between chlorine and arsenious oxide: As O + 4Cl + 4H O > 2As O + 8HCl The clear supernatant liquid gives percentages which are below, and the sediment percentages which are above, the average.
The proportions having been ascertained from these preliminary experiments, the alcohol and acid are then mixed accordingly, e.g., 300 of alcohol to 225 of acid. One or two grammes of stearic acid are added to the alcoholic acetic acid, and the clear supernatant liquid used for the experiments. If the olive oil is pure, the acids dissolve to a clear solution that remains so.
It is then discontinued, the mixture allowed to deposit for a few moments, and about two-thirds of the supernatant solution decanted; it is mixed with some more water, and these decantations repeated until they pass away without reaction, or by filtering it and washing on the filter; it is then dissolved in hot hydrochloric acid, this nearly neutralized, a solution of sesquichloride of iron is added, and again treated with an excess of chlorine.
The following method is but little known, although it deserves preference over many others. Add 7 oz. of quicklime to 1 3/4 pints of cold water. Let the mixture stand until the supernatant fluid is entirely clear. Then pour this off, and mix with it enough olive oil to form a thick cream, or rather to the consistency of melted and re-congealed butter.
Much time may often be saved by washing precipitates by decantation, i.e., by pouring over them, while still in the original vessel, considerable volumes of wash-water and allowing them to settle. The supernatant, clear wash-water is then decanted through the filter, so far as practicable without disturbing the precipitate, and a new portion of wash-water is added.
In some portable machinery, an intermittent tensile stress is applied of 15,000 pounds, sometimes rising to 20,000 pounds per square inch of section, without any evidence of weakness. Drop into the tube a particle of "acid magenta;" after again shaking the liquids together, the lower two zones will present different shades of red, while the supernatant hydrocarbon will remain without color. Amer.
After the lime has been thoroughly mixed it should be left for at least eight hours for the superabundant lime to subside, leaving the supernatant fluid a perfectly clear saturated solution of lime.
Agitate distillate with dry potassium carbonate, and draw off some of the supernatant fluid for testing. Tests. Odour. Dissolves camphor. With dilute sulphuric acid and bichromate of potassium turns green, and evolves aldehyde. Product of combustion makes lime-water white and turbid. =Methyl Alcohol: Wood Naphtha.= Used to produce intoxication by painters, furniture-polishers, etc.
If soluble starch is not at hand, potato starch may be used. Mix about 1 gram with 5 cc. of cold water to a smooth paste, pour 150 cc. of !boiling! water over it, warm for a moment on the hot plate, and put it aside to settle. Decant the supernatant liquid through a filter and use the clear filtrate; 5 cc. of this solution are needed for a titration.
When the reduction has been completed, the supernatant liquid is poured off, and the residue washed in the ordinary manner. Arsenic cannot be completely separated from either its aqueous hydrochloric acid, or from a solution to which ammonium oxalate has been added in excess.
Word Of The Day
Others Looking