Mercury thiocyanates

Rhodan-ion, n. thiocyanogen ion, CNS -kali, -kalium, n, potassium thiocyanate, -kalzium, n. calcium thiocyanate, -kupfer, n. cupric thiocyanate, copper(II) thiocyanate. -iSsung, /. thiocyanate solution, -metall, n. (metallic) thiocyanate, -methyl, n. methyl thiocyanate, -natrium, n, sodium thiocyanate, -nickel, m. nickel thiocyanate, -quecksilber, n. mercury thiocyanate, -salz, n. thiocyanate, -sdure, /. (Org. Chem.) thiocyan(at)o acid, -tonerde, /. aluminum thiocyanate. 

Mercury(II) chloranilate 700 Mercury(II) nitrate standard soln. of, 359 Mercury/mercury( II )-EDTA electrode (mercury electrode) 586 potentiometric titration of metallic ions with EDTA and, 588 prepn. of, 587 Mercury thiocyanate 700 Metaphosphoric acid in homogeneous precipitation, 426 Metal apparatus 93 Metal ion buffer 53... 

Mass effects due to some ions in salts. It is generally observed that there is a greater instability amongst compounds containing heavy atoms compared with elements in the first periods of the periodic tabie.This can be observed by analysing enthalpies of formation of ammonia, phosphine, arsine and stibine (see previous table for the last three). In the same way, it is easier to handle sodium azide than lead azide, which is a primary explosive for detonators. It is exactly the same with the relatively highly stable zinc and cadmium thiocyanates and the much less stable mercury thiocyanate. 

The method can be used for the direct determination of the chloride ion content in precipitation samples within the 0.05-5 mg/L range. Chloride ions will replace the thiocyanate ions in undissociated mercury thiocyanate. The thiocyanate ions thus released react with ferric ions to form a dark red iron-thiocyanate complex. 

DITHIOCYANATE MERCURY THIOCYANATE (DOT) MERCURY(II) THIOCYANATE THIOCYANIC ACID, MERCURY(2+) SALT... 

Figure 5.13. Determination of chloride by the mercury thiocyanate method with the hydrodynamic injection manifold in Fig. 5.12a, where C was 100 cm long and the volume of conduit L was 25 xL. The pumping rate x = z was 1.1 mL/min and the aspiration rate y was 3.0 mL/min, operated for 12 s. The detector was tuned at 490 nm. (a) Standard calibration run of samples in the range 10-50 ppm Cl (b) stopped-flow experiment with the 40 ppm Cl standard recorded at high paper speed to demonstrate the fast rate of reaction and (c) monitoring of the content of chloride in a solution of NaCl in which the analyte concentration was changed intermittently and measured at fixed time intervals by the system.

Test by mutual precipitation of zinc and cobalt with mercury thiocyanate ... 

Zinc ions react with mercury thiocyanate ions ... 

Procedure. A drop of the test solution, a drop of the cobalt solution, and a drop of the mercury thiocyanate solution are mixed on a spot plate or in a micro crucible. The sides of the vessel are rubbed with a glass rod for about 15 seconds. According to the amount of zinc present, a blue precipitate is formed, either at once, or at the longest within 2 minutes. In the absence of zinc, the precipitation begins only after 2-3 minutes. 

Alkali mercury thiocyanate solution 8 g HgClg and 9 g NH4CNS in 100 ml water. Allow to stand several days. 

The reaction (page 219) with ammonium mercury thiocyanate (violet... 

A drop of 2 iV sulfuric acid is placed on the surface to be tested, and allowed to react for about a minute. The drop is then taken up on filter paper impregnated with 0.1 % copper sulfate. The fleck on the paper is spotted with a drop of ammonium-mercury thiocyanate solution (see page 498). Zinc is revealed by a violet color. The color is due to the formation of a compound containing Zn[Hg(CNS)4] and Cu[Hg(CNS)4] which, however, does not have the color of a mechanical mixture of these components (see page 219). 

When the fleck is red, owing to ferric thiocyanate from large amounts of iron, a drop of ammonium fluoride solution is added. It discharges the ferrithiocyanate color, and the violet of the zinc-copper-mercury thiocyanate becomes clearly visible. 

This test for zinc is not reliable when cobalt and nickel are present because they too form colored double thiocyanates with mercury thiocyanate. 

Ammonium mercury thiocyanate Trisodium pentacyano-/>-nitroso- — 605... 

Hydrogen chloride Measurement duct Once/day Mercury thiocyane (II) absorption spectroscopy JIS K 0103... 

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