Solveeit Logo

Question

Question: Gold sol can be prepared by: A. hydrolysis of gold (iii) chloride B. oxidation of gold by aqua-r...

Gold sol can be prepared by:
A. hydrolysis of gold (iii) chloride
B. oxidation of gold by aqua-regia
C. peptization
D. treating gold (iii) chloride with metallic zinc
E. reduction of gold (iii) chiori de with formalin solution

Explanation

Solution

Gold sol may be a sort of multimolecular colloid as large no of molecules get combined to create the colloidal particles. It's a charged and a lyophobic sol.

Complete step by step answer:
Colloidal state of matter may be a state during which the dimensions of particles is such that they'll meet up with paper but not through animal or vegetable membranes.
The coagulation of a colloid carried out by an electrolyte doesn't take place as long as the added electrolyte has a minimum concentration within the solution. The minimum concentration of the electrolyte that has got to be added to one litre of the sol , in millimoles so on bringing forth complete coagulation is named the flocculation value or coagulation value of the electrolyte for the sol.
Based on the nature of interaction between dispersed particles and dispersing medium it's divided into two types namely lyophilic and lyophobic colloids.
1. Lyophilic Sols
The word Lyophilic implies liquid-loving. During this sort of colloidal solvent, the form has great affinity for the dispersing medium. In such colloids, the form doesn't get easily precipitated and also the sols are quite stable. The solids obtained after evaporation are also reconverted to the sol state by simply agitating them with the dispersing phase. samples of lyophilic sols include sols of gelatine, gum, proteins, starch and certain polymers in organic solvents. Such sols are called reversible sols. If water is the dispersing medium, these are called hydrophilic sols.
2. Lyophobic Sols
The word Lyophobic implies liquid-hating. During this style of sols, the form has little affinity for the dispersing medium. These sols, when compared to lyophilic sols, are less stable. These sols are easily coagulated (or precipitated) when small amounts of electrolytes are added, by shaking or by heating. As the precipitated mass can not be brought back to the colloidal state by simply shaking them up with the medium of dispersion, so these are irreversible. Hence, these sols are called irreversible sols. Samples of lyophobic sols consist of sols of metals along with their insoluble compounds like oxides as well as sulphides. they have stabilizing substances for his or her preservation. If water is that form, these are called hydrophobic sols.
Now gold sol will be prepared by reducing gold(III) chloride with formalin solution.

So the correct option is (d).

Note: The lyophilic sols can be said to be more stable than lyophobic sols. The soundness of lyophilic sols is because of two factors.