Gold numbers 201 sols

Gold number may be defined as the number of milligrams of a protective colloid which will just stop the coagulation of 10 ml of a given gold sol on adding 1 ml of 10% sodium chloride solution . 

If no protective colloid is present in the gold sol, it will turn from red to blue. The smaller the gold number of a protective colloid, the greater is its protective power. 

Problem Gold number of starch is 25. Calculate its amount to be added intd 100 ml of gold sol so that it is not coagulated in presence of 10 ml of 10% NaCl solution. 

Heller and Pugh (1954) used a slight modification of Zsigmondy s gold number experiment to measure the effect that four samples of poly-(oxyethylene) had on the stabUity of a Faraday gold sol when potassium chloride was added. Their results are shown in Table 2.2. Listed therein are the values of the critical concentration of potassium chloride (cJ q), required to induce the red- blue transformation in the gold sol in the presence of the polymer at a given concentration (1 -0 g dm ). This concentration of polymer... 

Zsigmondy gold number chem The number of milligrams of protective colloid necessary to prevent 10 milliliters of gold sol from coagulating when 0.5 milliliter of 10% sodium chloride solution is added. zig-mon-de gold. nom-bor zwitterlon See dipolar ion. tsfid-orj.an ... 

Table 7 gives a fev values of the gold numbers and oi anaiogously defined silver numbers, rubin numbers (sol of congorubin) sulphur numbers, Prussian blue-numbers and iron oxide-numbers ... 

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