Gold powder

Figure 2 Ion-sensitive plate detector showing the species produced by the SSMS analysis of a Y203 Eu203 mixture compacted with gold powder.

A mother solution of HAUCI4 (10 g/L of Au) was prepared dissolving gold powder (5g) in aqua regia (100 mL) by... 

Sanchez-Loredo, M. G. Grote, M. Solvent extraction and hydrochemical preparation of gold powders with dithizone derivatives. International Solvent Extraction Conference, Cape Town, South Africa, Mar. 17-21, 2002, 934-939. 

The hexafluorouranate(V) with the formula [Au(CO)2]+[UF6] was obtained by dissolving gold powder in liquid anhydrous HF containing UF6 in a CO atmosphere. The crystalline product is stable at room temperature but decomposes on warming above ca. 50 °C. Two decomposition pathways were observed which afford either Au metal, CO gas, and a residue of UF6, or Au metal, a mixture of CO and COF2 gas, and a residue of UF5. The compound was... 

Y. lizuka, T. Tode, T. Takao, K. Yatsu, T. Takeuchi, S. Tsubota, and M. Haruta, A kinetic and adsorption study of CO oxidation over unsupported fine gold powder and over gold supported on titanium dioxide, J. Catal. 187(1), 50-58 (1999). 

Ontko, A.C. and Angelid, R.J. (1998) Effects of alkyl chain length on the adsorption of n-alkyl isocyanides (R-N=C) on gold powder. Langmuir, 14,1584—91. 

Attempts have been made to increase the strength of GICs by reinforcing them with metal fibers or flakes. Silver and gold powder have been mixed or fused with the glass powder part of the cement. Such approaches have resulted in improved wear resistance. The properties and clinical use of metal-reinforced glass-ionomer cements have recently been reviewed by Wasson (1993) and hence will not be repeated here [172]. 

Fig. 9.2.2 SEM images of gold powders obtained by reduction of HAuCI4-3H20 in ethylene glycol in presence of PVP at different temperatures (a) 100°C, (b) I20°C. (c) 150"C, (d) 170°C. (From Ref. 14.)...

When the pulverulent gold has entirely deposited, the liquid must be decanted or filtered off with the greatest precaution. Care must bo taken that not the smallest particle of the gold powder is allowed to pass away with tho liquid, A little hydrochloric acid, which must ho quite free from any admixture of nitric acid, is then to be poured upon the precipitate. This will remove any iron or other metallic impurities without dissolving the gold. The latter is then to be washed, at least six times, with successive portions of distilled waterj and lastly, it is transferred to a email porcelain Or platinum crucible, in which it is heated over a spirit lamp, till the last portions of water are expelled. It ought, in fact, to bo raised to a red heat, or even to be fused with a small quantity of borax and nitrate of soda, as formerly recommended, to expel the last traces of ohlorlde of silver. 

Yellow sand or gold powder. It is used in suns where it produces golden yellow rays. It is a reddish yellow sand mixed with... 

A solution of 6.64 g 3,4-ethylenedioxybenzaldehyde in 40 mL nitroethane was treated with 0.26 g anhydrous ammonium acetate and held at reflux for 3 days. TLC analysis showed that there was much aldehyde remaining unreacted, so an additional 0.7 g ammonium acetate was added, and the mixture held at reflux for an additional 6 h. The excess nitroethane was removed under vacuum. The residue was dissolved in 30 mL hot MeOH which, with patience and slow cooling, finally deposited a heavy yellow-gold powder. This product l-(3,4-ethylenedioxyphenyl)-2-nitro-propene melted at 95-96 °C and weighed 6.03 g when air dried to constant weight. Recrystallization from either MeOH or EtOAc gave the product as a yellow solid, but without any improvement in mp. 

Gold powder, 4 14, 15 Graham s salt, 3 88, 104 Guanidonium nitrate, 1 94 from calcium cyanamide, 1 97 from dicyanodiamide, 1 96... 

For a gorgeous—and easy—presentation, brush these brownies with metallic gold powder, or mix both silver and gold for a glittery effect. 

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