MCQ Detailed View

In organic chemistry, selecting the appropriate separation technique depends on the physical and chemical properties of the compounds in the mixture. For nonvolatile, nonpolar organic compounds, methods like distillation and gas chromatography are not suitable, as they require volatility and often smaller sample sizes.

1. Distillation:
This technique works well for separating volatile liquids based on boiling points. However, nonvolatile compounds cannot be vaporized easily, making distillation ineffective for such mixtures.

2. Extraction:
Liquid–liquid extraction is useful for separating compounds based on differences in solubility between two immiscible solvents (commonly organic solvent and water). While effective for simple mixtures, it is not practical for separating large numbers of similar nonpolar compounds, especially when they lack polarity differences.

3. Gas Chromatography (GC):
GC is a powerful analytical technique, but it is best suited for small amounts of volatile compounds. Nonvolatile compounds cannot be analyzed effectively with GC, and it is not a practical method for preparative (large-scale) separation.

4. Column Chromatography:
This technique is ideal for separating large quantities of organic compounds, especially when they are nonvolatile and nonpolar. In column chromatography, the mixture is loaded onto a column filled with a stationary phase (commonly silica gel or alumina). A suitable solvent or solvent mixture (mobile phase) is passed through the column, allowing different compounds to move at different rates based on their interactions with the stationary phase. Nonpolar compounds interact weakly with the polar stationary phase, allowing controlled separation using appropriate solvent systems.

Column chromatography is widely used in organic synthesis and natural product isolation because it can handle large-scale separations and works effectively with compounds that cannot be distilled or analyzed by GC. It is also versatile, as it can separate mixtures of both polar and nonpolar compounds by adjusting the solvent polarity.

Therefore, the most appropriate method for separating a large quantity of nonvolatile, nonpolar organic compounds is Column Chromatography (Option D).