字幕列表 影片播放 列印英文字幕 Our topic for today is Simple Distillation. The process of heating a liquid mixture to form vapor and then cooling that vapor to get a liquid is called simple distillation. Distillation is used to purify a liquid by separating the components of a liquid mixture. Let us perform an activity to understand Simple Distillation. Take a mixture of acetone and water in a distillation flask. Put a thermometer in it. Connect the flask to a water condenser. The condenser has cold water running through its jacket to keep the temperature cool. Keep a beaker at the outlet of the condenser. Heat the mixture, keeping an eye on the thermometer. When temperature hits 56 degrees celsius, acetone starts to vaporize. These vapors condense in the water condenser. The condensed acetone gets collected in the beaker. When all the acetone vaporizes, water is left in the flask, acetone is collected in the beaker. In this way, acetone and water get separated by simple distillation. Boiling point of water is 100 degrees celsius. Boiling point of acetone is 56 degrees celsius. As there is sufficient difference between their boiling points, these components can be separated by simple distillation. Simple distillation does not work properly when difference between 2 boiling points is less than 25 degrees celsius. This is because the components do not get separated and purified completely. If we repeat this process multiple times, we will be able to separate these 2 components. However, as this is very time consuming, a special type of distillation called fractional distillation is used.