Statement I : For colloidal particles, the values of colligative properties are of small order as compared to values shown by true solutions at same concentration.
Statement II : For colloidal particles, the potential difference between the fixed layer and the diffused layer of same charges is called the electrokinetic potential or zeta potential.
In the light of the above statements, choose the correct answer from the options given below
Statement II : For colloidal particles, the potential difference between the fixed layer and the diffused layer of same charges is called the electrokinetic potential or zeta potential.
In the light of the above statements, choose the correct answer from the options given below
- A.Both Statement I and Statement II are false
- B.Statement I is true but Statement II is false
- C.Statement I is false but Statement II is true
- D.Both Statement I and Statement II are true
Show answer and solution
Correct option: B
Solution
Statement I is true because colligative properties depend on the number of solute particles. Colloidal particles are aggregates of many molecules forming large clusters, so the number of dispersed particles per unit concentration is far fewer than in a true solution, giving smaller colligative effects.
Statement II is false because zeta potential is defined as the potential difference between the fixed (Stern) layer and the diffused layer of OPPOSITE charges surrounding the colloidal particle — not same charges. The fixed layer carries charge of one sign, and the diffuse layer contains counterions (opposite charges); the potential drop between these two layers is the electrokinetic/zeta potential.
Statement II is false because zeta potential is defined as the potential difference between the fixed (Stern) layer and the diffused layer of OPPOSITE charges surrounding the colloidal particle — not same charges. The fixed layer carries charge of one sign, and the diffuse layer contains counterions (opposite charges); the potential drop between these two layers is the electrokinetic/zeta potential.
[JEE Main 2023 · 24 Jan · Shift 1 · Paper-1(B.E./B. Tech.)]