Tungstic

_Tungsten Blue_ is an oxide formed by the action of various deoxidizing agents on tungstic acid. ❋ George Field (N/A)

Next followed the discovery of tungstic acid, and in 1783 he added to his list of useful discoveries that of glycerine. ❋ Unknown (1904)

It is weighed when cold, and is the trioxide or "tungstic acid" (WO_ {3}), which contains 79.31 per cent. of tungsten. ❋ Cornelius Beringer (1886)

It must be remembered when calculating the percentage that (with the exception of the silica, tungstic acid, and tin) the determinations have been made on 1 gram of the sample. ❋ Cornelius Beringer (1886)

The tungstic acid is dissolved, and separated as ammonic tungstate, and, after evaporation, is gently ignited, the heat being increased towards the end. ❋ Cornelius Beringer (1886)

The tungstate of ammonia requires simple evaporation on the water-bath and gentle ignition in order to cause the tungstic acid to be left in an almost pure state; possibly, it may carry a little silica. ❋ Cornelius Beringer (1886)

This solution gives with hydrochloric acid a white precipitate of tungstic acid, which becomes yellow on boiling, but the separation is not complete. ❋ Cornelius Beringer (1886)

For the assay of minerals containing tungsten these reactions are only occasionally taken advantage of for testing or purifying the separated tungstic acid. ❋ Cornelius Beringer (1886)

This may be got rid of by boiling in aqua regia, and dissolving out the tungstic acid which has been liberated by means of ammonia. ❋ Cornelius Beringer (1886)

~ -- Digest the residue with about 50 c.c. of water and a few c.c. of dilute ammonia for a few minutes, and filter; collect the filtrate in a weighed porcelain dish, evaporate to dryness, ignite, and weigh as tungstic acid, WO_ {3}. ❋ Cornelius Beringer (1886)

~ -- The decomposition and solution of natural tungstates is difficult to effect owing to the separation of tungstic acid; the method of treatment is as follows: -- Boil the finely-powdered substance with hydrochloric acid or aqua regia till it apparently ceases to be attacked; dilute, filter, and wash with dilute hydrochloric acid. ❋ Cornelius Beringer (1886)

~ -- The acid filtrate from the silica and tungstic acid is treated with sulphuretted hydrogen. ❋ Cornelius Beringer (1886)

Tungsten occurs in nature only in the oxidised state, or as tungstic acid (WO_ {3}), either free, as in wolframine, or combined with oxides of manganese and iron, as in wolfram, or with lime, as in scheelite. ❋ Cornelius Beringer (1886)

Alloys containing tungsten leave tungstic acid after treatment with nitric acid or aqua regia. ❋ Cornelius Beringer (1886)

The residual tungstic acid is fixed, so that when the ammonia has been driven off it may be strongly heated without loss. ❋ Cornelius Beringer (1886)

Any silica present will be left undissolved; it should be separated and weighed, and its weight deducted from that of the tungstic acid found. ❋ Cornelius Beringer (1886)

On treatment with hydrochloric acid or aqua regia they are decomposed; the yellow tungstic acid separates and remains insoluble. ❋ Cornelius Beringer (1886)

On boiling with hydrochloric acid they are both liberated, and remain for the greater part (all the niobic) in the insoluble residue with the tungstic acid. ❋ Cornelius Beringer (1886)

Tungsten itself is insoluble in nitric acid or aqua regia; but is converted into tungstic acid (WO_ {3}) by prolonged and strong ignition in air. ❋ Cornelius Beringer (1886)

Wolfram, an analysis of, 296 tungstic acid in, 296 ❋ Cornelius Beringer (1886)