Question

Haemoglobin and gold sol are examples of:
A) Positively charged sols
B) Negatively charged sols
C) Positively and negatively charged sol respectively
D) Negatively and positively charged sols,respectively

Answer 1

Hint: In a continuous liquid media, a sol is a colloid made up of very tiny solid particles. The Tyndall effect is seen on the sols, which are fairly stable. Blood, coloured ink, cell fluids, paint, antacids, and dirt are all examples. Dispersion or condensation can be used to make artificial sols. Ball milling and Bredig's arc method are two methods for dispersing materials to colloidal dimensions. The use of dispersion agents can help to keep sols stable. Sols are frequently employed in the sol–gel process.

Complete answer:
A high number of atoms or smaller molecules of a material cluster together during dissolution to produce colloidal species (less than 1 nm). Multimolecular colloids are the result of this process. For example, gold sol and sulphur sol.
This is because haemoglobin is only found inside RBCs; outside the RBCs, in the bloodstream, it is very poisonous. The -vely charged phospholipid heads on the RBC membrane inhibit induction of the +ve charge on its surface, thereby isolating the charge from the colloid. Although blood is a negatively charged colloid and haemoglobin is a positively charged colloid, they do not coagulate in the body. Proteins and glycoproteins are encased in a fluid lipid bilayer that gives red blood cells their viscoelastic properties. The negatively charged surface of the RBC membrane is caused by glycoproteins, which produces a repulsive electric zeta potential between cells.
Because a high number of molecules mix to create colloidal particles, gold sol is a multimolecular colloid. It's a lyophobic, negatively charged sol. Negatively charged metal sols are common. As a result, gold sol has a negative charge. Adsorption of negatively charged $Au{O_2}^{-}$ ions on dispersed phase particles causes the negative charge.
Hence option (C) is correct.

Note:
A colloid is a combination in which one component is suspended in another by microscopically distributed insoluble particles. Some definitions, however, stipulate that the particles must be dispersed in a liquid, while others broaden the concept to include aerosols and gels.