Zeta potential and electrophoresis mcqs are important concepts in the study of colloidal systems and colloidal chemistry. Understanding these Zeta potential and electrophoresis mcqs topics is essential in various fields such as biochemistry, materials science, and environmental science. Zeta potential is a key property of colloidal particles, and electrophoresis is a technique that allows us to study these particles’ behavior in an electric field. This zeta potential and electrophoresis mcqs article will explore the significance of zeta potential, its measurement, and its relation to electrophoresis.

Zeta Potential: What Is It?

Zeta potential is the potential difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particles in a colloidal solution. It reflects the electrostatic potential at the slipping plane, the boundary where fluid velocity is equal to zero. This measurement is crucial because it helps determine the stability of colloidal dispersions. The higher the zeta potential, the more stable the colloid is, as particles repel each other more strongly, reducing the likelihood of aggregation.

In simple terms, zeta potential is a measure of the electrostatic repulsion or attraction between particles in a colloidal solution. When particles have a high zeta potential, they are less likely to clump together, meaning the colloidal solution remains stable. In contrast, a low zeta potential can cause particles to aggregate, leading to instability in the dispersion.

Zeta potential is typically measured in millivolts (mV). A zeta potential greater than +30 mV or less than -30 mV usually indicates a stable colloidal solution, while values closer to zero suggest instability. The value of the zeta potential is influenced by several factors, including the ionic strength of the medium, pH, and the nature of the particles themselves.

Importance of Zeta Potential in Colloidal Systems

In zeta potential and electrophoresis mcqs, the study of zeta potential is particularly important for controlling and optimizing the stability of colloidal systems. In industries such as pharmaceuticals, food processing, and cosmetics, maintaining the stability of colloidal suspensions ensures consistent product quality and performance. For example, in drug delivery systems, the stability of nanoparticles is crucial to ensure that the drugs are delivered effectively to the targeted areas.

In this zeta potential and electrophoresis mcqs, zeta potential plays a pivotal role in controlling the interaction between particles, which can affect various properties such as viscosity, particle size, and the ability of the particles to aggregate or disperse. By adjusting parameters like pH or the concentration of stabilizing agents, manufacturers can modify the zeta potential to achieve the desired stability in their colloidal systems.

Electrophoresis: The Technique

In zeta potential and electrophoresis mcqs, electrophoresis is a laboratory technique used to separate particles in a colloidal solution based on their charge and size by applying an electric field. This technique relies on the movement of charged particles through a medium, typically a gel or liquid, under the influence of an electric field. The rate at which particles move depends on their zeta potential, size, and the strength of the electric field.

In electrophoresis, particles with a high zeta potential will move faster than those with a low zeta potential because the greater the charge, the stronger the electrostatic interaction with the electric field. This principle is particularly useful in biochemistry and molecular biology for separating proteins, nucleic acids, and other molecules based on their size and charge.

Zeta Potential and Electrophoresis MCQs: The Connection

In Zeta potential and electrophoresis mcqs, zeta potential is directly related to the movement of particles during electrophoresis. As mentioned earlier, the zeta potential determines how easily particles move in an electric field. A colloidal particle with a high zeta potential will experience a greater force in the electric field, leading to faster movement. This makes the measurement of zeta potential an essential part of understanding how particles will behave in electrophoresis.

In applications such as protein electrophoresis, the zeta potential helps predict how proteins will migrate in the gel or solution. For instance, proteins with a higher negative zeta potential will move towards the positive electrode more quickly, while positively charged proteins will move towards the negative electrode. The separation process is based on both the charge and size of the molecules, which is why understanding the zeta potential is essential for optimizing the technique.

Applications of Zeta Potential and Electrophoresis  MCQs

Both zeta potential and electrophoresis mcqs have wide-ranging applications across various fields. In the medical field, electrophoresis is used to separate different types of proteins and nucleic acids, which is crucial for diagnostics and genetic research. By understanding the zeta potential of different molecules, scientists can fine-tune electrophoresis techniques to achieve more efficient separations.

In environmental science, zeta potential and electrophoresis mcqs are used to study the behavior of pollutants in water. For instance, the stability of colloidal particles in wastewater treatment can be affected by changes in the zeta potential. By measuring zeta potential, researchers can predict how particles will behave during the treatment process, helping to design more effective treatment methods.

In materials science, zeta potential and electrophoresis mcqs, zeta potential plays a critical role in the stability and functionality of nanomaterials. For example, in the production of nanostructured materials, controlling the zeta potential ensures that the particles remain stable and do not agglomerate, which is crucial for maintaining the material’s properties. Electrophoresis is also used to separate nanomaterials for further study or use in various applications, such as sensors or drug delivery systems.

Zeta Potential and electrophoresis MCQs with Solved Answers:

1.  Which of the following make up an isotonic triad?

   • (a) Ge3278,As3377,Ga3174\mathrm{Ge}_{32}^{78}, \mathrm{As}_{33}^{77}, \mathrm{Ga}_{31}^{74}Ge3278​,As3377​,Ga3174​

   • (b) Ar1840,K1940,Ca2040\mathrm{Ar}_{18}^{40}, \mathrm{K}_{19}^{40}, \mathrm{Ca}_{20}^{40}Ar1840​,K1940​,Ca2040​

   • (c) C613,C712,N714\mathrm{C}_{6}^{13}, \mathrm{C}_{7}^{12}, \mathrm{N}_{7}^{14}C613​,C712​,N714​

   • (d) C614,O816,N715\mathrm{C}_{6}^{14}, \mathrm{O}_{8}^{16}, \mathrm{N}_{7}^{15}C614​,O816​,N715​

   • Answer: (d)

2. Blood cells do not shrink in blood because blood is:

   • (a) hypotonic

   • (b) isotonic

   • (c) equimolar

   • (d) hypertonic

   • Answer: (b)

3. What is the amount of urea dissolved per litre if aqueous solution is isotonic with 10% cane sugar solution? (mol. wt. of urea = 60)

   • (a) 20 g/L

   • (b) 19.2 g/L

   • (c) 17.54 g/L

   • (d) 1.67 g/L

   • Answer: (c)

4. At certain temperature a 5.12% solution of cane sugar is isotonic with a 0.9% solution of an unknown solute. The molar mass of solute is:

   • (a) 60

   • (b) 46.17

   • (c) 120

   • (d) 90

   • Answer: (a)

5. A solution containing 10 g per dm³ of urea (molecular mass = 60 g mol⁻¹) is isotonic with a 5% solution of a non-volatile solute. The molecular mass of this non-volatile solute is:

   • (a) 200 g mol⁻¹

   • (b) 250 g mol⁻¹

   • (c) 300 g mol⁻¹

   • (d) 350 g mol⁻¹

   • Answer: (c)

6. “Given below are two statements:

   • Statement I: In the coagulation of a negative sol, the flocculating power of the three given ions is in the order: Al³⁺ > Ba²⁺ > Na⁺

   • Statement II: In the coagulation of a positive sol, the flocculating power of the three given salts is in the order: NaCl > Na₂SO₄ > Na₃PO₄

   • Answer: Statement I is incorrect but Statement II is correct.

   • Answer: (d)

7. “The correct order of coagulating power of the following ions to coagulate the positive sol is (I) [Fe(CN)₃]⁴⁻ (II) Cl⁻ (III) SO₄²⁻”

   • (a) I > II > III

   • (b) III > II > I

   • (c) II > III > I

   • (d) I > III > II

   • Answer: (d)

8. The coagulation of 200 mL of a positive colloid took place when 0.73 g of HCl was added to it without changing the volume much. The flocculation value of HCl for the colloid is:

   • (a) 100

   • (b) 0.365

   • (c) 200

   • (d) 1000

   • Answer: (a)

9. Which of the following substances show the highest colligative properties?

   • (a) 0.1 M BaCl₂

   • (b) 0.1 M AgNO₃

   • (c) 0.1 M urea

   • (d) 0.1 M (NH₄)₃PO₄

   • Answer: (d)

10. For As₂S₃ sol, the most effective coagulating agent is:

    • (a) CaCO₃

    • (b) NaCl

    • (c) FeCl₃

    • (d) Clay

    • Answer: (c)

11. The coagulating power of an electrolyte for arsenious sulphide solution decreases in the order:

    • (a) Al³⁺ > Ba²⁺ > Na⁺

    • (b) Cl⁻ > SO₄²⁻ > PO₄³⁻

    • (c) PO₄³⁻ > Cl⁻ > SO₄²⁻

    • (d) Na⁺ > Al³⁺ > Ba²⁺

    • Answer: (a)

12. Which of the following ions will have maximum flocculating power for coagulation of As₂S₃ solution?

    • (a) Na⁺

    • (b) Al³⁺

    • (c) Mg²⁺

    • (d) Ba²⁺

    • Answer: (b)

13. Match the entries in Column-I with the terms used to show the effect of process in Column-II:

    Column-I	Column-II
    I. Ferric hydroxide is mixed with arsenic sulphide solution	A. Double decomposition
    II. FeCl₃ is mixed with freshly prepared ppt of Fe(OH)₃	B. Coagulation
    III. H₂S gas is passed through arsenic oxide solution	C. Tyndall effect
    IV. A beam of light is passed through milk	D. Peptization

    Answer:

    • I → D (Peptization)

    • II → A (Double decomposition)

    • III → B (Coagulation)

    • IV → C (Tyndall effect)

14. Which of the following solution has the lowest osmotic pressure?

    • (a) 200 mL of 2 M NaCl solution

    • (b) 200 mL of 1 M glucose solution

    • (c) 200 mL of 2 M urea solution

    • (d) 200 mL of 1 M KCl solution

    • Answer: (b)

15. The most effective coagulating agent among the options for Sb₂S₃ solution is:

    • (a) Na₂SO₄

    • (b) Al₂(SO₄)₃

    • (c) CaCl₄

    • (d) NH₄Cl

    • Answer: (b)

16. For the coagulation of a negative solution, the species below, that has the highest flocculation power is:

    • (a) Ba²⁺

    • (b) Na⁺

    • (c) PO₄³⁻

    • (d) SO₄²⁻

    • Answer: (a)

17. 100 mL of 0.0018% (w/v) solution of Cl⁻ ion was the minimum concentration of Cl⁻ required to precipitate a negative sol in one h. The coagulating value of Cl⁻ ion is ____ (Nearest integer):

    • (a) 1

    • (b) 3

    • (c) 5

    • (d) 7

    • Answer: (a)

18. Zeta potential is:

    • (a) Potential required to bring about coagulation of a colloidal solution.

    • (b) Potential required to give the particle a speed of 1 cm s⁻¹

    • (c) Potential difference between fixed charged layer and the diffused layer having opposite charges

    • (d) Potential energy of the colloidal particles.

    • Answer: (c)

19. A colloidal solution is subjected to an electric field. The colloidal particles move towards anode. The amount of electrolytes of BaCl₂ and NaCl required to coagulate the given colloid is in the order:

    • (a) NaCl > BaCl₂ > AlCl₃

    • (b) BaCl₂ > AlCl₃ > NaCl

    • (c) AlCl₃ > NaCl > BaCl₂

    • (d) AlCl₃ > BaCl₂ > NaCl

    • Answer: (d)

20. If 0.2 moles of sulphuric acid is poured into 250 mL of water. Calculate the concentration of the solution?

    • (a) 0.8 M

    • (b) 8 M

    • (c) 0.2 M

    • (d) 0.02 M

    • Answer: (a)

21. The flocculation value of HCl for arsenic sulphide solution is 30 m mol L⁻¹. If H₂SO₄ is used for the flocculation of arsenic sulphide, the amount in grams of H₂SO₄ required for the same purpose is ____ (molecular mass of H₂SO₄ = 98 g/mol):

    • (a) 0.37

    • (b) 2

    • (c) 0.2

    • (d) 1

    • Answer: (a)

22. In the coagulation of a positive sol, the flocculating power of the ions PO₄³⁻, SO₄²⁻ and Cl⁻ decreases in the order:

    • (a) PO₄³⁻ > Cl⁻ > SO₄²⁻

    • (b) PO₄³⁻ > SO₄²⁻ > Cl⁻

    • (c) Cl⁻ > SO₄²⁻ > PO₄³⁻

    • (d) Cl⁻ > PO₄³⁻ > SO₄²⁻

    • Answer: (b)

23. Among the following the ion which will be more effective for flocculation of Fe(OH)₃ solution is:

    • (a) PO₄³⁻

    • (b) SO₄²⁻

    • (c) SO₃²⁻

    • (d) NO₃⁻

    • Answer: (a)