Friday, September 3, 2010

Todays class period was a rather unique one, but it started off the same as usual before it got interesting. We viewed Emma's blog in which she did an excellent job. Mr. Henderson then explained to us the photo situation. The photos that we would take on his camera for the blog would be on a website called dropshots.com.

We then looked at lab MM4. Separating Mixtures Lab and wrote down the purpose. Mr. Henderson then had us turn to page 18 in our Chemistry Basics packet to learn how we could separate sand, salt, and iron. It said that each method relies on the fact that the components have different physical properties which can be used in separation method.

To show us how this all worked, Mr. Henderson showed us a very fun and original demo. He talked about how sand had many variables in itself and could be split up into rocks, little pebbles, fine sand, and super fine sand. He used different sized screens to split these variables up going from the biggest openings to the smallest. As he started to 'shake it up,' he danced to one of his favorite songs by KC and the Sunshine Band. http://www.youtube.com/watch?v=8GtGY6tuDaA&feature=fvst

After that attention-grabbing demo, our class began the lab by weighing or finding the mass of the mixture by using the zero, or tare button. The mixture consisted of salt, sand, and iron and was a heterogeneous mixture because we could visibly see the differences in the substances. We then had to figure out how to separate them. First, we used a magnet to separate the iron because iron is magnetic. Next, we poured the rest of the mixture into water because we knew that salt was soluble, and we could filter out the sand. This is exactly what we did. We poured the mixture of sand, salt, and water through filter paper and a funnel which left behind the sand.

After that, we put the filter paper with the sand on a hot plate to dry it off. We did this because when we would weigh the sand to figure out its mass, we would not want to have water be part of that mass too.

We then weighed the iron and the sand to find out the mass in grams. To find the mass of the salt we subtracted the weight of iron and sand from the weight of the total mixture. We did this because salt was the only substance remaining so it would have to have the remaining weight of the mixture. For example, if the mixture weighed 2 grams, the iron weighed 0.24 grams, and the sand weighed 0.46 grams, then the salt would have to weigh 1.30 grams because 2 - (0.24+0.46) = 1.30. Furthermore, we calculated the percent of the salt, sand, and iron in the mixture by dividing its weight by the total weight of the mixture and multiplying it by 100. After doing that math, we wrote down our conclusion.

Class time was running out, and the Web Assign homework was assigned. We all left class 'shaking our booties' as Mr. Henderson put the song back on for the last couple minutes of class.