Separation Techniques

Compare Pure Substances to Mixtures Feel free to use google to help develop your thinking, but all answers should be your own. Separating solids from liquids – filtration Visit the BBC Bitesize website to complete the questions below. Separating mixtures - Bitesize Complete the table below. Separation Technique Types of solution Description Filtration Insoluble Solid - Liquid Sand and water Evaporation Soluble Solid - Liquid Copper sulfate and water Distillation Liquid - Solution Water and salt solution Chromatography Dissolved substances Plant dyes / Inks Sieving Solid - Solid Rocks and sand Explore the eSchoolToday website to answer the following questions or use your textbook. Methods for separating mixtures Complete the passage below by filling in the missing words. FiltrationThis process involves the use of a filter paper placed in a filter funnel. The funnel is placed in a beaker and the mixture of water and sand is poured into the funnel. The liquid part drains through the filter paper into the beaker, leaving the solid sand particles trapped on the filter. In filtration, the liquid part collected is called the filtrate and the solid bit that remained on the filter paper is called the residue.EvaporationEvaporation is the process by which water (and other liquids) changes from a liquid state to a vapor or gas state. Evaporation is great for separating a mixture (solution) of a soluble solid and a solvent. The process involves heating the solution until the solvent evaporates (turns into gas) leaving behind the solid residue.Simple distillationThis method is best for separating a liquid from a solution. In a way, the concept is similar to evaporation, but in this case, the vapor is collected by condensation. For example, if you want to separate water from a salt solution, simple distillation would be great for this.For example: A beaker of salt solution is heated to the boiling point of the liquid. As it boils, the liquid turns into vapor (gas). The vapor is directed through tubes (condenser) connected to another beaker. As the vapor goes through the tube, it is cooled down by running cold water around the tubes. This forces the temperature of the vapor to fall, causing the gas to turn into liquid again (condensation). The liquid is pure at this point, as it is free from salt. The process continues until all the liquid in the solution turns into vapor, leaving the salt residue. The distilled liquid is called a ‘distillate’.MagnetismMagnetism is ideal for separating mixtures of two solids with one part having magnetic properties. Some metals like iron, nickel and cobalt have magnetic properties whiles gold, silver and aluminum do not. Magnetic elements are attracted to a magnet.To use this method, spread out the mixture on a flat surface. Run a magnet bar over the surface. You will notice that the magnetic elements (iron filings) will be attracted to the magnet over it. After a number of runs, all the sand will be free from any iron filing.ChromatographyThis method is often used in the food industry. It is used to identify chemicals (coloring agents) in foods or inks. For example, if a scientist wants to know how many substances are in a particular blob of ink, paper chromatography can be used.For example: A blob of ink is smeared on a special paper called filter paper. The paper is placed in a trough of solvent. The solvent used depends on the chemicals in the ink blob. As the paper gets soaked upwards, it attracts the various chemicals in the ink blob. Because different chemicals have different rates of attraction to the solvent, the chemicals will travel upwards in different amounts. Sometimes, a chemical may not react at all. If a different solvent is used, all the various chemicals may travel at a completely different rate. How do we separate the seemingly inseparable? Watch the video to answer the questions below. List 3 properties that can be exploited to separate substances. Match the term to its use. Reverse osmosis Separate salt from see water Rotational force Separate red blood cells from plasma Distillation Separate petroleum from crude oil Sieving Remove gold from sand True or False. Chromatography is a chemical separation technique. True False Please read the article "what is separation science" on the link below, then fill in the following blanks. Separation science occurs within a laboratory context, involving the detailed study and controlled separation of mixtures. Mixtures are substances made from two or more elements and compounds which have been simply mixed together. When mixtures are created, no chemical reactions take place, and no chemical bonds are formed. Subsequently, mixtures can be separated into their component parts using techniques such as distillation and evaporation.Separation science is also referred to as “chromatography”, a term which combines the Greek words for colour (“chroma”) and writing (“graphein”). The various techniques and methods which underpin separation science inform the study of chemistry and biology, as well as engineering. Major advances in separation science have enabled biologists, chemists, pharmacists and environmentalists to make breakthroughs of their own. Genomics, drug discovery, DNA fingerprinting and ultra-trace residue analysis, for instance, would not be possible without recourse to the findings generated by separation science.Separation science, or chromatography, can be analytical or preparative. Analytical chromatography relies on small amounts of material and strives to measure the relative amounts of analytes in a mixture. No attempt is made to ready the material for future use. Preparative chromatography, on the other hand, seeks to separate a mixture into usable component parts. Preparative chromatography can be done on a small scale or an industrial scale.Separation processes convert mixtures into their constituent parts. Barring a handful of exceptions, almost every element and compound known to man is found in an impure – or mixed – state naturally. Before these impure substances can be put to good use, they must be separated into their constituent parts. In some instances, separation may result in a number of pure components. However, at other times, incomplete separation will suffice. Naturally occurring crude oil, for example, contains a mixture of different hydrocarbons and impurities. The refining process separates these substances into other, more valuable mixtures, such as gasoline, natural gas and chemical feedstocks. A series of separations takes place before the desired end products are considered usable.In general, separations are based on differences in physical or chemical properties, such as shape, density, size, mass and chemical affinity. When no clear difference can be identified, multiple operations are generally performed to achieve the desired separation. This is my first time using this software platform - what do you think? Please let me know if there were parts that were good or bad, if things didn't work on your computer, etc. If something didn't function, please also include information about the type of computer you are using AND what web browser you are using. Thanks!