Conclusions, Results and Analysis

Amanda and Stanton
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Material
Original Amount of Material (g)
Final amount of material (g)
Differences in material (g)
Aluminum
70
71
1
Iron Filings
81
83
2
Wood Shavings
3
4
1
Regular Salt
61
See below (B)
See below (B)
Sand
84
See below (A)
See below (A)
They were two beakers of mixtures that were not separated fully, which is why the table is incomplete.

The first beaker (A), which was originally the sand collection beaker, was a mixture of sand and murky water. There was approximately 50mL of sand, and 25mL of murky water. The entire beaker filled with the mixture weighed 233g. After the beaker was emptied and cleaned, it weighed 132g, meaning that there was 101g of murky water and sand in that beaker.

The second beaker (B), which was originally the salt collection beaker, was a mixture of iron particles, salt, sediment, and water. The entire beaker filled with the mixture weighed 389g. The empty beaker weighed 111g, meaning that there was 278g of materials in that beaker. They was also traces of materials in the funnel, spoon, tray, and two 500mL beakers. The spoon weighed 20g with materials on it, and 18g when it was cleaned. This means that there was 2g of materials on it. The first 500mL beaker had salt and particles of iron in it. It weighed 234g with the materials, and 233g without the materials. There were 1g of materials in that beaker. The second beaker, which contained iron particles, sand and salt weighed 237g with the materials, and 235g without the materials. This means that there were 2g of materials in that beaker.

As seen from the data table above, our procedure did not successfully separate all five materials completely. We examined our procedure and materials list more closely and have found information which we believe would help us separate the materials more successfully.

What happened to the materials that were lost?

Aluminum- The missing 1g of aluminum is easily accounted for: the scale we were using to mass our beakers has a margin of error of around +or- 1g. This accounts for the missing gram of aluminum.

Iron Filings- We ended up gaining 2g of iron filings, which is sand that was caught in the iron. In our revised procedure, we come up with a way to avoid this problem.

Wood Shavings- We ended up with 1g extra of wood shavings. The extra gram could be two possible things: either the margin of error of the scale, or some sand and iron that got on the wood.

Sand- We started with 84g of sand and ended with 101g of an odd mixture of sand and murky water. After measuring the amounts of material, we found 50mL of sand and 25mL of the murky water. The murky water ended up weighing 26g. When this is subtracted from the 101g, we end up with 75g. That means we lost 9g of sand in the process of the separation. The sand was scattered all over the floor, the tray, and in other materials. In beaker B, there was some sand mixed in with the salt we recovered. The sand was tough to keep track of, and our mistake caught up with us when we massed our materials.

Salt- The salt was a serious challenge. We started with61 g of salt. We ended with around 5g of actual salt material from various sources. Most of the lost salt was in the salt water which we failed to separate. Some other salt crystallized in other beakers, on the spoon, in the funnel, merged with sand, or lining the rims of various beakers involved in the experiment. Our analysis of the salt problem can be found in our revised procedure and analysis sections. It was by far the most challenging material to separate from the mixture.

Analysis (what went wrong with the procedure/materials list)


Original Procedure
  1. Pour heterogeneous mixture through the plastic funnel and through the fine metal sieve into one of the 500mL beaker
  2. Leave salt, sand, and iron filings in 500mL beaker
  3. Hand pick wood shavings and aluminum out from top of sieve and place into respective 200mL beakers
  4. Carefully sort through materials in 500mL beaker and use tweezers to pick out small pieces of aluminum or wood shavings that may have fallen through the sieve
  5. Insert three large magnets into 500mL beaker and wait until all iron filings have attached to magnets
  6. Pull magnets out of beaker with iron filings magnetically attached to magnets
  7. Scrape iron filings off of magnets and into respective 200mL beaker
  8. Take remaining mixture of salt and sand, and sift through sieve to make sure all particles of other items are not present
  9. Add approximately 300mL of pure water
  10. Stir mixture thoroughly with spoon until all of the sand has dissolved
  11. Use paper towels to clean up any spills if necessary
  12. Pour mixture through filter paper into a 500mL beaker until only sand remains on filter paper
  13. Take sand and put into respective 200mL beaker
  14. Place mixture on hot plate
  15. Set temperature on hot plate to 100* Celsius, 212* Fahrenheit, or 373.15* Kelvin
  16. Wait until mixture is boiling and all water has evaporated, leaving only salt in the beaker
  17. Take 500mL beaker off of the hot plate
  18. Pour salt into respective 200mL beaker

Original Materials List
· (1) Fine metal sieve approximately 5 in by 5 in
· (2) 500mL beakers
· 1,000mL of water
· (3) approximately 3 in by 3 in strong magnets
· (1) Hot plate large enough to heat a 500mL beaker
· (2) Filter paper sheets approximately 12.5cm diameter
· (1) Tweezers
· Several sheets of paper towels
· (1) spoon
· (1) 11cm diameter plastic funnel(8oz)
· Large green tray 30 centimeters by 42 cm


This is our original procedure and materials list. Obviously, it did not work as planned. After our experience in class performing these steps, we can see why some steps did not work. The first major problem happened right when we started. As we attempted to pour the mixture through the fine metal sieve, we immediately noticed that nothing could pass through, not even the sand and salt. The sieve was way too fine. Since nothing was passing through into the 500mL beaker, we had to think quickly of another way to separate the aluminum and wood shavings from the rest of the heterogeneous mixture (salt, sand, and iron filings.) This really slowed down the experiment because we had to pick through the entire mixture by hand. We could not use the tweezers or the spoon because the iron filings were attracted to them. This made step #3 irrelevant because the wood shavings and aluminum had to be hand picked out of the original mixture, not out of the sieve. Even then, the wood shavings had numerous iron, salt, and sand particles clinging to them. Hand picking was clearly not a desirable option, because it took an incredibly long time. The next problem came with steps 5 and 6. These steps contained and caused numerous problems. The first of these was that the magnets were way too strong. From one end of the table where the magnets were, the beaker with the iron, sand and salt was pulled across almost the whole table and collided with the magnets. This broke the beaker, spilling the mixture all over the table. It took us quite a long time to clean up, and some of the mixture had flown onto the floor and could not be recovered. After that problem was resolved, another one came. The wood shavings had gathered iron because they were not separated initially (problem with step 1). Therefore, when we used the magnets to gather the iron from the mixture, wood shavings were drawn out with the iron. Thus we had to spend even more time picking out wood shavings from the iron collection beaker.This first part of the experiment was supposed to be the easiest and the quickest. Because of all the problems that arose and all the time it took to complete this part, we had very little time to complete the next part of the experiment.
The next set of problems came with step 9. We already were extremely short on time, and the water took a very long time to filter through the filter paper. Also, when we added the water to the mixture of sand and salt, we noticed that they was a black, silvery coating on top of the beaker. This turned out to be particles of iron, and when we poured the mixture through the filter paper the iron particles were mixed with the sand. We were not sure how to separate the iron particles from the sand and the filter paper was taking too long anyway so we just gave up on that. Instead we simply poured the mixture through the sieve. We then scooped up the damp sand from the top of the sieve and put them into the salt collection beaker. We took the murky salt water and the black, silvery coating that had been poured through the sieve and put it into the salt collection beaker. Steps 12-16 had to be omitted because of time constraint. We did not leave ourselves enough time at the end of the lab to boil the mixture of salt and water. We had to just leave it in the room over night, and ended up with salt lining the rim of the beaker the next class period. This procedure and materials list ended up with a lot of errors, most of which could have been easily resolved. All revisions to the procedure that we think we should make are in the next section of the conclusion.
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Revised Procedure and Materials List and Explanation for Revisions

Revised Procedure
  1. Pour materials through plastic funnel and through fine metal sieve into 500mL beaker
  2. Leave salt, sand, and iron filings in 500mL beaker
  3. Hand pick wood shavings and aluminum out from top of sieve and place into respective 200mL beakers
  4. Carefully sort through materials in 500mL beaker and use plastic spoon to scoop out small pieces of aluminum or wood shavings that may have fallen through
  5. Cover the strong magnet with a paper towel
  6. Insert the magnet covered in a paper towel into the 500mL beaker and wait until all iron filings have attached to magnet
  7. Pull magnet out of beaker with iron filings magnetically attached to magnet
  8. Check iron filings attached to magnet for any wood shavings that may be attached
  9. Brush through the iron filings that have attached to the magnet to get rid of any sand that may have been caught
  10. Over the collection 200mL beaker for the iron filings, peel the paper towel off the magnet, releasing all the iron filings into the beaker easily
  11. Pour 300mL pure water into sand and salt mixture in 500mL beaker.
  12. Stir thoroughly with the plastic spoon to ensure sand is clearly at bottom of mixture and all salt is dissolved.
  13. Pour mixture, with water stirred thoroughly by the spoon, through sheets of filter paper into 500mL beaker.
  14. Whenever filter paper is covered in sand and cannot let any more water through, dump sand off of filter paper into 200mL collection beaker. Do this as many times as needed to completely separate sand from salt water.
  15. Place salt water (in a 500mL beaker) on hot plate and heat plate to 100* Celsius.
  16. Let mixture boil until water has evaporated and only salt remains.
  17. Pour salt out of 500mL beaker and into 200mL collection beaker.

Revised Materials List
  • (1) Metal sieve (big enough to pass sand particles, approximately 5mm holes)
  • (2) 500mL beakers
  • (1) pair of tweezers
  • Several sheets of paper towels
  • (1) Plastic spoon
  • (1) large strong magnet
  • (2) sheets of filter paper approximately 12.5cm in diameter
  • (1) hot plate large enough to heat a 500mL beaker
  • 500 mL of pure water
  • (1) large, strong magnet
  • (1) plastic funnel 11cm in diameter

We decided to make these changes based on things that went wrong in the procedure and/or materials list. With a fine metal sieve that actually allows salt, sand and iron filings to pass through it we will be able to save a great amount of time, and therefore be able to actually use the filter paper and the hot plate. Steps 5-7, involving the magnet, were changed/added because all three magnets together were far too strong for the iron filings, and caused a beaker to shatter. With just one magnet, and a paper towel on it, we can retrieve the iron filings more easily by just removing the paper towel over a beaker, all the iron filings will fall into the beaker. Step 9 needed to be added because in our observations we noticed numerous sand particles caught in the iron clump. We did have to brush through the iron caught on the magnet in order to get all the sand we could out of the iron clump. Steps 11-17 had to be edited in our real procedure because we ran out of time to boil the mixture. We decided to use a plastic spoon instead of a metal one because the iron was attracted to the metal spoon.
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Conclusion

All in all, our separation experiment turned out decently. If we use our revised procedure and materials list, we think we would be able to fully separate all the materials. It seems our main problems were with clarification of materials, rushing the process, and time management. If we were more careful with out materials, the beaker would not have broken, the wood wouldn't have mixed with all the iron, and we would have separated the items successfully. What we learned from this experiment is to be careful with materials and not to rush. We also learned to manage our time better, be more careful with our equipment, and think things through. It was a worthwhile experiment that has greatly improved our understanding of common substances and fundamental properties.
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