Identify the statement which is correct with respect to surface phenomenon. (a) Osmotic pressure of rubber sol will be same as that of sucrose solution having same mass mixed in same mass of water. (b) A gas may show physisorption at low temperature and chemisorption at high temperature. (c) Soap sol of sodium palmitate will coagulate near cathode in electrophoresis. (d) Gold sol on mixing with starch sol causes stabilization of starch sol.

Osmotic pressure is a fundamental concept in chemistry and biology that relates to the movement of solvent molecules through a semipermeable membrane. It results from the tendency of a solvent to equalize solute concentrations on both sides of the membrane.

For example, when rubber sol (a colloidal solution with rubber particles) and a sucrose solution have the same mass mixed in the same amount of water, they will not have the same osmotic pressure. This is because osmotic pressure is not just about the mass of the substance dissolved in water but about the number of particles. Rubber sol particles are much larger than sucrose molecules, meaning there will be fewer particles in the same mass, leading to a lower osmotic pressure for the rubber sol when compared to a sucrose solution with the same mass concentration.

Adsorption plays a crucial role in various chemical applications, such as catalysis and separation processes, and it refers to the accumulation of substances at the surface, rather than in the bulk of a solid or liquid.

Adsorption can be classified into two main types: physisorption and chemisorption. Physisorption occurs at lower temperatures and involves weaker forces, like van der Waals forces, causing temporary adherence of gas molecules to the surface. Chemisorption happens at higher temperatures when chemical bonds form between the adsorbent and adsorbate, leading to a much stronger and typically irreversible adherence. Hence, a gas may exhibit physisorption at a low temperature, and as the temperature rises, the adsorption can transition to chemisorption due to the increase in kinetic energy allowing the gas molecules to overcome the energy barrier for bond formation.

Electrophoresis is a technique used to separate charged particles under the influence of an electric field. It is often used in laboratories to analyze mixtures of proteins, DNA, or other charged molecules.

In a typical setup, charged particles will migrate towards the electrode of opposite charge. For instance, negatively charged particles, such as those in a soap sol of sodium palmitate, will move toward the positively charged anode. This principle is important in identifying the movement and separation of compounds in a mixture and is fundamental in processes like DNA sequencing. The statement about sodium palmitate coagulating near the cathode is incorrect, as it implies the movement of negatively charged particles to a negatively charged electrode, which is opposite of the process of electrophoresis.

Colloids are mixtures where one substance is dispersed evenly within another. Maintaining the stability of colloids is important for many industrial and food products. Colloid stability can be influenced by various factors including the presence of electrolytes, pH levels, and the addition of other substances.

For example, the addition of starch sol to gold sol does not inherently promote stabilization; there is no direct interaction that increases the stability of the starch colloid. Colloid stability is often managed through steric stabilization, where a barrier of molecules prevents the particles from coming close enough to aggregate, or electrostatic stabilization, where a charge on the colloid particles prevents them from clumping together. In some cases, stabilization can be achieved through an increase in viscosity or by the formation of a gel network that entraps the particles.