Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 28, 2025
When the amount of manganese is small, the separation of the two elements takes place very rapidly, and the results are accurate. If the amount of manganese is more than double that of iron, the separation of the latter will take a much longer time. As has been already mentioned in the determination of manganese as peroxide, its precipitation from ammonium oxalate is not complete.
The plates were exposed in the sensitometer as usual, except that it was found convenient in several cases to use a larger stop, measuring 0.316 cm. in diameter. The following table gives the absolute sensitiveness of several of the best known kinds of American and foreign plates, when developed with oxalate, in terms of pure silver chloride taken as a standard.
The electrolytic separation of cobalt is much more easily and rapidly effected when the potassium oxalate is substituted by the corresponding ammonium salt, as the latter forms a soluble double salt with the cobalt compounds.
If the double oxalate is submitted to electrolysis, the whole of the lead is separated out in its metallic state, but it is so rapidly oxidized by the air that it is very seldom that it can be dried without decomposition even when the operation is conducted in a current of illuminating gas. The electrolytic estimation of this element cannot be recommended.
It should be noted that the acid oxalate and the acid tartrate each contain one hydrogen atom replaceable by a base, while the tetroxalate contains three such atoms and the oxalic acid two. Soda ash is crude sodium carbonate.
The red composition used for making red flambeaux and percussion signals consists of 1,800 parts of chlorate of potash, 300 of oxalate of strontia, 300 of carbonate of strontia, 48 of whitewood charcoal, 240 of boiled oil, 6 of oil, and 14 of gum lac. A red or white Lamarre flambeau consists of a sheet rubber tube filled with one of the above-named compositions.
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.
The electric current decomposes the potassium oxalate into the carbonate, so that a precipitate of cobalt carbonate is simultaneously formed with the separation of the metallic cobalt.
No. 2: Water 100 c.c.; citric, 1½ gr.; sodium sulphite, 25 gr.; pyrogallol., 12 gr. Solution No. 2 is for its better keeping qualities preferable to Dr. To develop, mix 100 c.c. of water with 40 min. of No. 1 and 50 min. of No. 2. The picture appears quickly and more vigorously than with iron oxalate. If it is desirable to decrease the density of the negatives, double the quantity of water.
Neutral potassium oxalate is added in excess to the solution of a cobalt salt, and the clear solution of cobalt potassium oxalate submitted to electrolysis. The intense red color of this solution is soon changed into a dark green; the latter diminishing in intensity as the metal is deposited at the negative electrode.
Word Of The Day
Others Looking