Gold sol prepared by reduction of gold salts is stabilized by adsorbed negative ions on its surface. If a small amount of a strongly hydrated lyophilic colloid such as gelatin is added before adding an electrolyte, the gold sol becomes more resistant to coagulation. This protective effect is best explained by:

Answer: Gelatin forms a protective hydrophilic coating around the lyophobic gold particles, reducing their tendency to aggregate.

• A Gelatin is said to completely and permanently neutralize the entire surface charge carried by every gold particle present
• B Gelatin forms a protective hydrophilic coating around the lyophobic gold particles, reducing their tendency to aggregate
• C Gelatin is said to chemically react directly with the gold atoms themselves to form a brand new compound
• D Gelatin is said to noticeably raise the temperature of the surrounding sol, and this is what prevents coagulation