Dimensional Analysis

Dimensional Analysis is used to convert one quantity to another.

 

 

The most important thing when using dimensional analysis is knowing your conversion factors! Details and extra practice can be found on the following website and video: http://www.alysion.org/dimensional/fun.htm https://www.youtube.com/watch?v=lAan6L9UjsE

Measurement

We explored concepts of Significant Figures in class. This refers to the figures that were measured. The easiest way to explain is through the following picture:

This is applied in problems with when you are multiplying and dividing because the answer has to be rounded to the smallest number of sig figs. The following link is extremely helpful in explaining sig figs and even includes links on the sides for explaining sig figs in addition and subtraction, and multiplication and division.  Also check out the extra practice links at the top of the videos, as they are extremely helpful! https://www.khanacademy.org/math/arithmetic/decimals/significant_figures_tutorial/v/significant-figures

 



Classification of Matter

In class, we learned about classifying matter. We covered topics such as intramolecular which is ionic, covalent, metallic where the break changes the identity of the metal, and intermolecular associates the neighbors and includes hydrogen bonds, and when broken, the phase changes. For a clearer explanation of this you can watch this video: https://www.youtube.com/watch?v=GnswLP4t6d0 Another thing we learned about is physical property changes, they can be observed without changing identity; whereas, chemical property changes can only be observed when a substance changes into another. Check out this link for more information: http://antoine.frostburg.edu/chem/senese/101/matter/faq/physical-chemical.shtml We also covered separation techniques with focus on filtration, distillation, and chromatography. These techniques along with a little info about the classification of matter can be found on the following video: http://study.com/academy/lesson/states-of-matter-and-methods-of-separating-mixtures.html I also found a very helpful chart for classifying matter.

 



Aspirin Lab Day 2

Day 2 consisted of isolating the product. We did this by using a Buchner funnel and filter paper as shown in the picture below.

Day 2 Set-Up

We emptied the contents of our beaker from day one that crystalized over night into the funnel and rinsed it with ice cold water then let the water suction out for a few minutes. We used tweezers to remove the filter paper with the product on it and set it in a watch glass to transport to its drying area.

Aspirin Lab Day 1

We started the process of making aspirin by combining 5g of salicylic acid, 7mL of acetic anhydride and 8 drops of concentrated sulfuric acid. Then, it was time to heat the starting materials. We made a hot water bath and boiled for 15 minutes. This is what the hot water bath set up looked like:

When the 15 minutes were up, we allowed the flask to cool for 3 minutes on a hot plate and added 15mL of ice cold water to the flask and swirled it to mix contents then set it up on the lab bench to crystalize over night.

Test

We have just completed our unit and took the unit test. The test covered a number of topics that I have been discussing in my previous blogs such as atomic theories, subatomic particles, calculating average atomic mass, radioactivity, and fission and fusion. I was very nervous for this test because I wasn't familiar with any topics beforehand and the content seemed harder than the last unit, but I feel like I did well and can only hope for the best results now! The part of the test that confused me the most was calculating percent abundance since I did not review that as much as I should have before the test. I found a link to help me review for the next test in hopes I do better on that next time. These are some practice problems with embedded videos for extra explanation when needed: http://www.chemteam.info/Mole/AverageAtomicWeight.html