Free Analytical Chemistry MCQs with Answers

11. Which of the following analytical method is based on scattering of radiation?

• A. Emission spectroscopy
• B. Colorimetry
• C. Polarimetry
• D. Turbidimetry
• E. Paleography

Explanation: Turbidimetry measures the reduction in the transmission of light due to scattering by suspended particles in a solution. The amount of light scattered is related to the concentration of the particles.

12. Which of the following analytical method is based on the rotation of light radiation?

• A. Refractometry
• B. Polarimetry
• C. Interferometry
• D. Mass spectrometry

Explanation: Polarimetry is a technique that measures the angle of rotation of plane-polarized light as it passes through an optically active (chiral) substance. This rotation is used to determine the concentration and purity of chiral compounds.

13. Which of the following analytical technique is based on the refraction of radiation?

• A. Conductometry
• B. Refractometry
• C. Coulometry
• D. Polarography

Explanation: Refractometry measures the extent to which light is bent, or refracted, when it passes from one medium to another. The refractive index is a characteristic property of a substance that can be used for identification and concentration measurement.

14. Which of the following analytical technique is used for the separation of an interfering substance or analyte from the mixture?

• A. Precipitation
• B. Distillation
• C. Electrode position
• D. All of the above

Explanation: Precipitation separates components based on solubility, distillation separates based on boiling point, and electrodeposition separates based on electrochemical properties. All three are valid methods used to separate components of a mixture for analysis.

15. Which of the following method is based on the solubility difference between the analyte and the unwanted components?

• A. Distillation
• B. Complex formation
• C. Electrodeposition
• D. Precipitation

Explanation: Precipitation is a separation technique where a reagent is added to a solution to selectively convert the analyte into an insoluble solid (precipitate). This allows it to be physically separated from the other soluble components of the mixture.

16. Which of the following technique is based on deposition of the analyte at appropriate electrode by the passage of the electric current?

• A. Chromatography
• B. Dialysis
• C. Electrodialysis
• D. Electrodeposition

Explanation: Electrodeposition, also known as electroplating or electrolytic deposition, is a process that uses an electric current to reduce dissolved metal cations so that they form a coherent metal coating on an electrode.

17. Which of the following methods is the most common method for separation of liquid components from a mixture?

• A. Dialysis
• B. Solvent extraction
• C. Chromatography
• D. Distillation

Explanation: Distillation is a widely used and effective method for separating components of a liquid mixture based on differences in their boiling points. The component with the lower boiling point vaporizes first and is then condensed and collected separately.

18. Which of the following analytical method is used for the separation of dissolved components from solutions?

• A. Chromatography
• B. Dialysis
• C. Solvent extraction
• D. Electrophoresis

Explanation: Solvent extraction is a method used to separate compounds based on their relative solubilities in two different immiscible liquids, usually water and an organic solvent. The compound partitions between the two phases, allowing for its separation.

19. Which of the following analytical technique is used for separating similar substances by preferential adsorption or partition between two phases?

• A. Distillation
• B. Dialysis
• C. Solvent extraction
• D. Chromatography

Explanation: Chromatography is a powerful separation technique where components of a mixture are separated based on their differential distribution between a stationary phase and a mobile phase. This distribution is governed by processes like adsorption and partition.

20. Which of the following technique is used to separate substances of high molecular weights (proteins, enzymes) of different charges?

• A. Dialysis
• B. Electrophoresis
• C. Solvent extraction
• D. Distillation

Explanation: Electrophoresis is a technique used to separate macromolecules like proteins based on their size and net electric charge. An electric field is applied to the sample, causing charged molecules to migrate at different rates.