Assessinfg Purity of Nacl from Rock Salt

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Extracting NaCl from Rock Salt and assessing its purity
Aim
The aim of this experiment was to obtain a pure product from a solution through the processes o extraction, filtering and evaporation. Introduction
Extraction is used when trying to separate or purify a product. For an extraction to be successful the substance used to make the solvent should readily dissolve. The substance used in this practical was rock salt. The liquid used should not react with the substance that needs extracting. In laboratories extracting is used by chemists to purify samples and also analyse unknown samples. However, in the pharmaceutical industry, pharmacists rely on this technique to collect information about chemical properties of a compound that they are researching. They then use this information to pass on to professionals who are working in developing compounds and investigating the effects of these compounds on the human body. Additionally, environmental remediation projects (services which remove environmental problems such as removing any contaminants found in ground water or sterilising an area where there has been an oil spill) use an extractor to separate any contaminants. In our experiment we used the technique of extraction to test the purity of the substance. Purity is when a substance is free from contamination. It is important for a substance to be pure so that chemists can study its properties. The purity of a substance is vital in the production of food and drugs; the government has set daily guidelines of how much of a substance can be consumed. Any impurities which are found in a drug or medicine can reduce the effectiveness. There are many ways of determining whether a product is pure or not, for example: filtration, crystallization, infrared spectroscopy, mass spectrometry, nuclear magnetic resonance spectroscopy, chromatography, electrophoresis, immunochemical reactions, ultracentrifugation and titration. The method used in this experiment was titration. Decreasing the purity in a substance is very common because contamination can be hard to avoid. However things that can reduce the purity in my experiment could be because: the equipment used to handle the substance may not have been rinsed before use, the filter paper or the funnel used had other chemicals on it which we did not know about, the table or the bench had spilled chemicals which could lead to contamination.

http://www.wisegeek.com/what-is-solvent-extraction.htm
http://www.wisegeek.com/what-is-environmental-remediation.htm Method:
Apparatus and Materials used:
*
* Weighing boat
* Spatula
* Evaporating Dish
* Beaker
* Funnel
* Filter paper
* Volumetric flask
* Rock salt
* Pestle & Mortar
* Weighing Scales
* Stirring rod
* Conical flask
* Hydrochloric acid
* Pipette
* Distilled water
* Syringe
* Methyl orange indicator

Extraction
1. Take some rock salt and put it in to a mortar.
2. Using a pestle crush the rock salt until it is powder. 3. Then weigh the beaker and add 1g of the powder into the beaker. 4. Add 50cm3 of distilled water into the beaker. And stir thoroughly using a glass rod. 5. Using a funnel and filter paper filter the solution in the mixture into a prewighed evaporating dish. 6. Wait to for a week for the mixture to evaporate.

7. Now weigh the evaporating dish and sodium chloride crystals. Making it into a standard solution
1. Scrape out the sodium chloride crystals from the evaporating dish and put them in a weighing boat and weight them. 2. Transfer the crystals in to a beaker.
3. Add 50cm3 of distilled water making sure that the solute has completely dissolved using a stirring rod. 4. Put a funnel on top of a volumetric flask and pour the liquid in the beaker down the rod and into the flask. 5. Rinse the beaker with more distilled water and pour it into the volumetric flack and do the same for the stirring...
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