Dividing a Mixture. Kylie Hunter. Partners: Melanie, Conor, Maria. October 15, 2010

Transcription

1 Dividing a Mixture Kylie Hunter Partners: Melanie, Conor, Maria October 15, 2010

2 Method: Purpose: The purpose of this lab was to accurately separate the coffee grounds oil garlic saltsalt water mixture, one substance at a time, until we get clear, drinkable water. Materials: 4 pairs of goggles 2 pairs of latex gloves 125 ml of the mixture 4 medium sized beakers 2 flasks coffee filters/filter papers 1 ring stand 3 funnels rubber tube foil and a pen activated charcoal water distillation apparatus Procedure: Put on goggles and make sure everyone is wearing close toed shoes. This is done before starting the lab to ensure safety in case something was to drop or shatter. Collect materials and the 125 ml of mixture. Use filter paper over a medium beaker and pour the substance into the filter paper until the liquid is fully filtered into the beakers and the coffee grounds are left on the paper. Filter the mixture over 3 beakers at the same time. When the mixture is completely filtered, throw away the filters with the coffee grounds and combine the filtered liquid into one beaker. The rest of the mixture (oil, salt, water, and garlic) were drained through the filter paper but the coffee grounds were not. This was our first step because we thought that eliminating the solids from the mixture would make the separation process easier later one in the lab. We had three breakers draining at the same time to speed up the process. At one point the filter paper slipped and we had to start that beaker over again to drain the coffee grounds out. Set up the ring stand and attach the rubber tube to the end of one of the funnels and set the funnel in the ring. Place an empty beaker under the funnel. Then folding the tube in half to prevent and liquid from draining, pour the liquid into the funnel and let it sit until the oil has settled at the top of the mixture (keeping the tube tightly clamped). Then slowly let the tube go to let the liquid drain slowly. Pug the tube again once the oil gets close to the end of the funnel. Remove the filtered beaker and release the oil that is trapped at the end of the hose into a separate beaker. Rinse out the beaker that held the original liquid part of the mixture and place that under the funnel. Repeat until there seems to be no oil left in the liquid. While this was not able to filter out the oil 100%, it filtered out the oil to the point where the tiny amount of oil left would not interfere with the rest of our experiment and would be filtered out completely later in the process. Originally we thought we could us eye droppers to suck up the oil once it settled at the top of the liquid but were afraid we would get too much of the rest of the liquid as well. We were unfamiliar with this method when we were working on the pre lab until we looked up ways to separate mixtures and found a

3 method of dividing water and oil with materials similar to those that were provided for our lab. We continued to filter the oil out multiple times and had to rinse the beakers each time to get the oil that clung to the sides out so the oil wouldn t end up back in our liquid. Once the oil is separated out, mix activated charcoal in with the garlic powder saltwater mix. Then cover the liquid and charcoal mix with aluminum foil and label it with our group s names and put it in a drawer to sit overnight. The next day, remove the foil and set filter paper to sit over 3 medium beakers. Then pour the liquid mixed with charcoal over the filters to filter out the charcoal and garlic. Throw away the filters when they become too full of charcoal. If the filtered liquid still smells garlicky put more charcoal in and let it sit for 15 minutes. Repeat the filtering process. At the end of the filtering process combine the filtered salt water into one beaker. At first we were unsure of how to filter out the garlic powder until we looked up ways to filter garlic powder out of water. When mixed in with a liquid, the activated charcoal absorbs organic material such as the garlic powder and when we filtered the charcoal out we filtered out the garlic as well. The charcoal didn t filter the garlic completely the first time so we had to go through the process again. During the filtering we had to re filter because the filter paper got heavy and clogged with the charcoal and slipped down. We got the charcoal back in the filtered salt water so we had to go back and re filter it again. Finally we took the filtered salt water and put it in the water distillation apparatus. We poured the salt water in the apparatus and put a beaker at the end of the apparatus. We then waited until we had clean, clear, distilled water. At first we thought we would have to use the Bunsen burner and heat the salt water to get the water to evaporate and then catch the water condensation. The water distillation apparatus does that essentially. The flask that the salt water is poured into is heated and the steam goes up to the top of the glass. The steam runs into the tube coming off the side. Cold water circulates the tube and cools the steam so it condenses. The condensation runs down the tube and drips into the clean beaker. We used this last rather than at the beginning so the oil and coffee grounds and garlic salt wouldn t get stuck in the apparatus and congeal on the sides.

4 Data: Test: Test 1 (coffee grounds): Filtering Test 2 (oil): Funnel and the rubber tube Test 3 (garlic salt): Activated charcoal and filtering Test 4 (salt): Water distillation apparatus Observations: We filtered the mixture through the filter paper to catch the coffee grounds. The liquid filtered through (including the oil which we were worried wouldn t go through the filter) until all that was left on the filter paper were the coffee grounds. This was difficult because it was a sort of guess and check and had to be repeated multiple times because we couldn t get all the oil out right away. A couple times we let the mixture level go too low and we ended up with oil in our mixture and had to repeat the process again. This test took awhile because we let the charcoal sit in the mixture overnight. When we were filtering the charcoal/garlic out of the liquid we had to change the filters a few times in each beaker because the charcoal clogged up the paper. The paper got heavy with the charcoal and a couple times the charcoal fell in the filtered out liquid and we had to filter the beaker again. We had to go through the whole charcoal process again because the charcoal didn t take all the garlic out the first time. We did this test as a class because we ran out of time. We watched the slightly murky water boil into a steam and watched the steam condense in the column off the side of the flask until the salt water finally dripped into the clean beaker as distilled water.

5 Results: The purpose of the lab was to separate out each part of the mixture one substance at a time. We started out pre lab brainstorming ideas of how to separate each substance out. We used the itouches to look up different ways to separate out oil and garlic salt because we figured out how to filter out the coffee grounds and the salt. We later were told to use the water distillation apparatus to separate the salt and water. Our procedure was pretty straight forward and we didn t have to make too many changes to our materials used and we only had to change how we separated the salt and water. For each test except the water distillation we had to go through the filtering and the processes multiple times to make sure each substance was thoroughly separated.

6 Discussion: A few things could have contributed to our experiment going wrong. First off, we would ve had a problem and accidently let too much oil stay in our mixture, or the mixture could have accidently been poured a little over the side of the filter paper in any of the tests involving filtering. We could have accidently gotten extra charcoal in the mix after our third test.