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| Question | Answer |
| What is Chromatography useful for? | Chromatography is a useful analytical technique for separating and identifying components of a mixture. |
| What do the different types of Chromatography depend on? | The equilibrium set up when a compound distributes itself between the two phases. |
| What is the stationary phase? | The phase that stands still. |
| What is the mobile phase? | The phase that moves over. |
| What do different compounds do with these two phases? | They distribute themselves between the two phases at different speeds. |
| Where is the spotted sample placed? | On the stationary phase |
| What can the stationary phase be made of? | Silica gel or filter paper (for paper chromatography) |
| What is another name for the suitable solvent? | Mobile phase |
| What develops on the stationary plate? | Spots for each compound in the mixture? |
| What is the locating agent used to develop the spots? | Ninhydrin. The amino acids show up in shades of purple? |
| What other locating agents are there? | Iodine and UV light. |
| If a spot is closer to the solvent front what does this mean? | There is a greater affinity for mobile phase therefore gets carried further. |
| If the spot if closer to the pencil line what does this mean? | There is greater affinity for stationary phase therefore does not get carried far by mobile phase. |
| What affects the distance made by a particular substance? | 1) Nature of substance 2) Total distance traveled by the solvent front. 3) Conditions under chromatography: -Temperature -Type of Paper/Thin Layer Plate -Type of Solvent |
| What is the Rf value? | Distance that the substance travels relative to the solvent front. |
| Equation of Rf Value | A/X Distance traveled by spot/distance traveled by solvent front |
| Rf Value and Standard Contitions | Under similar conditions, a component should always travel at the same speed. Its identity can be found by comparing the distance it moves relative to the solvent. |
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