Chromatography Lab Report

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I. Definition of a Mixture- A mixture is defined as two or more substances that are mixed together, but not held together by chemical bonds. They retain their own chemical identities and can be easily separated back to their original states using physical methods e.g. filtration, distillation. There is also little to no energy changes to the substances and have variable compositions. An example of a mixture is- Salt water (saline solution)- This mixture, containing the compounds water H20 and salt NaCL which can be created by adding and mixing a small amount of salt (NaCL) into water (H2O) until dissolved, as the compound salt (NaCL) is a soluble substance which means it dissolves when mixed into a liquid. It can then be separated by heating…show more content…
To complete this, I would firstly get a piece of chromatography paper, a pencil, a dish of solvent (water), a ruler and some string or similar to attach the paper to. I would then draw a line onto the paper using a pencil and ruler, across the bottom of the page 1-2cm away from the edge of the paper. I would then put a dot of green ink onto the line on the paper. Once this was done I would attach the paper to the string in such a position that the end of paper with the ink dot, was touching the dish containing the solvent that I would place underneath, I would also be careful to make sure that the solvent was not touching the ink dot. The solvent would then start traveling up the piece of paper causing the ink to travel upwards with it and the different colored pigments that make up the green ink would start to separate as it traveled. Once the solvent had traveled as far up as it could, but while it was still wet, I would draw a line on the paper using a pencil and ruler from the bottom line up to the point that the solvent ends. I would observe that the green inks yellow and blue pigments had separated and spread up the paper. I would then measure the distance that each pigment had traveled from the starting point of the green ink (the line at the bottom of the paper) and divide this by the distance that the solvent had traveled to find out the RF…show more content…
When iron is exposed over a period of time to water and oxygen, the water allows the oxygen to combine with the iron. This oxidizes the iron and causes corrosion. It also changes the chemical structure of the iron which bonds with oxygen and forms the compound iron (III) oxide Fe2O3 or iron (II) oxide FeO. This oxidation, corrosion and chemical change of structure is non reversible therefore is a chemical not physical change. How to tell that wood that has been burnt on a bonfire and gave off a lot a smoke has gone through a chemical change-When wood burns it releases substances that can’t be retrieved e.g. carbon dioxide CO2 and water vapors H2O. It also has a change in energy and gives off heat and light. Once wood has finished burning you are left with ash, which can include calcium carbonate CaCO3 and carbon oxide CaO, as there is no way to get the wood back to its original state the process is non reversible, therefore it has gone through a chemical

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