Week 3 Reflection

In chemistry this week we were introduced to many new topics, including how to accurately record and represent the data for an object, for this was becoming slightly hectic for us during class. Many people had a variety of ways for measuring an object and quite frankly, it was beginning to confuse everyone. Luckily, Mr. Abud effectively showed us how to accurately and precisely measure an object in a way that everyone agreed upon and could follow easily. We were informed that you should only include the decimal points you know for sure and then an extra one is allowed for estimation. We were able to come to the consensus that since our measures are limited by the tools we use, our answers cannot be more precise than our least precise measure. Also, we were informed of the various way in which we could represent the data found, such as the algabraeic and linguistic forms. Due to these new set stanadards, measuring and recording data has never been easier.

Another new concept that was introduced to us this week was density. Density is defined as the compactness of particles in an object; the equation for it is d=m/v or mass divided by volume. When shown in a graph, the steeper the line is, the more dense that object was. One of the experiments we conducted this week was to help us learn how to measure the density of a liquid, or in this case, water. We first measured the mass of the empty container before filling it with water to the designated spot and recording its mass then. This would help us further differenciate the actual mass of the water without the container's mass interfering. The water was then poured into a graduated cylinder to help us calculate the volume, which is also a vital part of the density equation. This process was then repeated five times to help show us the varying densities at different levels of water.

New questions arose about density after the water experiment was completed and inquired about the densities of similar liquids. We decided to then conduct an experiment involving eight total liquids: water, vegetable cooking oil, Coca-Cola, Diet Coca-Cola, Sprite, fruit punch, Dr. Pepper, and apple juice. The work for this lab was divided amongst the five groups, but omitted the need for a group to measure water, for each group had previously done this. From there, we were each able to effectively measure and record all the necessary data for our designated liquid in class. The results were then posted online for all to see and compare with their results. The next day, each group gave a short description of what liquid(s) they measured and the density for each. Ranking from least dense to most dense, our conclusion was as follows: 1) vegetable cooking oil - 0.88g/ml; 2) Diet Coca-Cola - 0.93g/ml; 3) apple juice - 0.95g/ml; 4) water - 0.98g/ml; 5) fruit punch - 1.0g/ml; 6) Dr. Pepper - 1.018g/ml; 7) Sprite - 1.02g/ml; 8) Coca-Cola - 1.05g/ml. After we came to this consensus, a valid point was brought up: all of the liquids had very close densities. Mr. Abud then revealed to us that the density of water is technically 1.000g/ml after many tests had been conducted to prove this. From this, we were able to generalize that these densities are so close to that of water because they partly consist of water.