Monday, September 8, 2014

Analysis and Reflection of Mixtures Lab

Analysis Questions:

1.The formulas for salt, sand, and iron are NaCl, SiO2, and Fe. Are these substances elements or compounds.
Salt is a compound made up of two elements, Na and Cl. The sand would also be a compound, but the iron is only an element.

2. Are any of the substances magnetic? Is magnetism a physical or chemical property? Explain.
Only the iron is magnetic. Magnetism is a physical property because a physical property does not change the substance while a chemical property is a property that can change the substance's chemical composition. After reacting with the magnet the iron still remains the same which would imply that magnetism is a physical property.

3. Are any of the substances soluble in water? Is solubility a chemical or physical property. Explain.

The salt is the only substance soluble in water. Solubility is a physical property because the soluble substances can return to their original forms and are not chemically changed. For example, If I were to dissolve salt into water and then boil the water completely I would be left with the original salt.

4. Does the combination of salt and sand produce a new compound or a mixture? Explain.
The combination of salt and produce a new heterogeneous mixture because the salt and sand are not in a fixed composition and can be separated by physical properties.

5. Describe the results of the filtration. Which substance remained on the filter paper? Is the filtrate (the liquid that passed through the funnel) a pure substance? Explain.
After we filtered out the mixture, we were left with salt water in the beaker and the sand on the filter. The filtrate (salt water) would not be a pure substance but a homogeneous mixture because the salt and water do not chemically combine and can be separated.

6. Compare the accepted values and the experimental values collected for the mass of your mixture components. Try to explain why the numbers might be the same or different.
Because our group didn't get the chance to find the mass of the salt we didn't get to see the accepted. If the numbers were the same though it is probably because everything was measured and separated very precisely and if it were different it could be because either there was a problem in measuring the mass or there could have been a mistake made in the process of separation.

7. Discuss difficulties with separation methods.
Separation methods are difficult because there is a lot of room for error and it is hard to get your results down to the exact gram. For example, there could be drops of water left on a beaker when trying to pour all the liquid into a separate container. This would later affect the mass.

8. Connect and apply what you learned in this lab to a separation technique that is regularly used in everyday life. What might be the same or different about this technique or set of methods? (you may research, but be sure to cite it!) 
An example of separation that occurs often in everyday life is making coffee. You must use a filter to make coffee and put ground coffee on top and then pour water through. The concept of the filter with water is similar to what we did in the lab. A difference though, is that although we do measure how much coffee we put inside the machine, it does not have to be as accurate as the lab by making sure not one gram is out of place.

Reflection and Conclusion:
During the pre-lab, our group had to begin to understand the materials we would we be working with the next day and begin to formulate ideas on how we should conduct the experiment to complete the lab. After the small experiments which were testing out the three substances of the mixture, we found out that the iron  had a magnetic property and the salt had a soluble property, so we realized that these properties would be our means of separation. The properties of each part were the same as when they were mixed together as a whole which allows for this separation to work. At first it was difficult to come up with the procedures for the lab, but we eventually figured out how to use all the tools we were given to our advantage so we could conduct the lab. For our lab, we came up with the idea to first extract all the iron with a magnet and separate that. Then we put the sand and salt in water and dissolved the salt. After this we poured the beaker into a filter and separated the sand. In order to get the salt that had passed through the filter we boiled the salt water. To see the full procedures, see the procedure list. During the lab we found it very difficult to separate every little gram of each substance and there was a lot of room for error. For example when separated the sand it was still wet with the salt water, so when we measured the mass it was not completely accurate. In order to prevent this problem from happening in the future, we would wait longer for the sand to dry and the water to evaporate. Our lab was also incomplete because we did not have enough time for the water to completely boil. Because of this, we were unable to find the total mass of the salt. Despite this issue, our results seemed to be accurate and overall, I felt like we were able to get a good understanding of each substance and it's properties.

1 comment:

  1. Thanks for this post. I have been looking for something like this for year’s thank you! Buy our Salt Filtration System to get water free from solid & oils. Our saltwater filtration systems are unique and proven alternatives to traditional water softeners

    ReplyDelete