Which of the following characterize gas-liquid chromatography?Gas mobile phaseLiquid stationary phaseSeparation based on polarityRoom-temperature column conditions

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11ecba2d_12ba_0c8e_a3bf_b1f3d0fd8871_MD0008_00 Gas-liquid chromatography is a technique used to separate molecules in a mixture based on their boiling points. A gas chromatograph consists of an injection port, mobile and stationary phases, a column in a heated oven, a detector, and a computer for data analysis. The mobile phase is an inert gas such as helium or nitrogen (Number I), and the stationary phase is a liquid that coats a solid support on the inside of the column (Number II). A small amount of a liquid mixture is injected into the gas chromatograph, and the compounds in the mixture are vaporized by heating. The vapors then travel through the column in a heated oven to the detector. The most volatile molecules (low boiling points) spend more time in the gas phase than they spend interacting with the stationary phase of the column, so they migrate to the detector rapidly. However, molecules with higher boiling points condense more readily and spend more time interacting with the liquid stationary phase. These molecules make their way through the column slowly as the temperature in the oven increases. (Number III) Components of a mixture are separated by boiling point rather than polarity. Although polarity impacts a compound's boiling point, it is not the only determining factor. A sufficiently large nonpolar molecule can have a higher boiling point than a polar molecule. For example, a nonpolar 20-carbon alkane chain has a higher boiling point than a polar 4-carbon carboxylic acid (343 °C vs 164 °C) and would move through the column more slowly despite being non-polar. (Number IV) The column must be placed in a heated environment to allow volatile molecules to remain in the gas phase. Columns kept at room temperature would not separate the molecules. Educational objective: Gas-liquid chromatography is a technique that separates compounds in a mixture based on boiling point. The mobile phase is an inert gas, and the stationary phase is a liquid that coats the column, which is in a heated oven. The molecule with the lowest boiling point will reach the detector before molecules with higher boiling points.

Which of the Following Characterize Gas-Liquid Chromatography?Gas Mobile PhaseLiquid Stationary