Week 21

This week in Chem, we continued our exploration of counting particles. In the beginning of the week, we continued our work from last week counting the number of particles in a certain amount of something. To count these particles we use moles. We practiced by using dimensional analysis to make sure our units came to cancel out and leave us with whatever we needed to find. So we came to possibly one of the coolest experiments we've done so far, in my opinion at least. We electrolyzed water, separating molecules into hydrogen and oxygen gases. To do this, we had a trough filled with a sodium hydroxide solution and two prongs sticking in the water. We placed test tubes filled with water on each prong, and connected two wires to the bottoms of the prongs under the trough. These wires were connected to a genecon that we consistently spun. The test tubes began to fill with hydrogen gas in one, and oxygen gas in the other! We went until we had 7.0mL of hydrogen gas and 3.5mL of oxygen gas. This proportion also proves that the water formula is H2O. There was double the amount of hydrogen gas as oxygen gas. We could then find the number of particles by again doing the dimensional analysis to find how many moles in each. We found that there were 1.6x10^-4 moles of oxygen, and 3.2x10^-4 moles of hydrogen. Another proof of the formula for water, H2O! It shows us how the empirical formula works out to be H2O with double hydrogen as oxygen. We finished the week off with an assessment covering everything we've done the past 2 weeks, and I feel very comfortable with it. I'm starting to like how we're learning more like the other classes have and am curious to see how the rest of the year plays out.

Week 20

During week 20, we mainly worked with the concept of moles. At the beginning of of the week, though, we did the experiment lighting the magnesium on fire again. This time we finished it though and ended up concluding that the magnesium had gained mass from lighting it on fire. This means that the product must've taken in particles from the air. Then, indirectly we began working with moles. We started in class with six containers containing six materials in each. We were asked to then find the relative mass of each by comparing them all to one of the items. Mr. Abud then introduced the mole to us. A mole answers the question of "how many" and is equal to 6 x 10^23 particles. Also, molar mass is the mass of a substance on the periodic table except measured in grams. You can find the amount of molecules or weights of moles with various substances, and can make it easier if you incorporate the phrase "for every" while working with your information. The week was a bit repetitive, but was necessary to get the idea into our heads.

Week 19

Week 19 was an odd week for the Chem team. On Monday, we tried an experiment in which we mixed hydrogen chloride with a pebble of zinc to produce a gas. However, the experiment didn't produce any gas. So, the next day we tried the same experiment using a more potent hydrogen chloride. The two reactants were placed into a flask that was plugged with a stopper that connected it to a trough. We then had a bell jar in the trough filled with water. As the gas was produced, water left the bell jar until there was only gas left. We carefully removed the jar, trying to let the least amount of gas escape using a watch glass under it. To test if it was combustible, we lit a match and held it under the jar. Quickly removing the watch glass, the gas escaped and combusted down onto the table and made a popping noise. We found out that the gas produced here was hydrogen glass. We then moved to practicing balancing equations which is still very difficult for me. I will need more practice with it. While working with this concept we learned a few things. First, we know that the total number of particles in a closed system gets conserved which helps us balance equations. Then, we learned all the diatomic elements using an acronym. Dr. Hofbrincl, standing for: hydrogen, oxygen, fluorine, bromine, iodine, nitrogen, and chlorine. Finishing the week, Mr. Abud did an experiment for us lighting a piece of magnesium on fire. It was a very cool experiment, watching the magnesium ignite and get so bright so quickly. However, we didn't get to finish it and mass the magnesium afterwards. We would have had an assessment at the end of the week but had the pleasant surprise of a snow day!

Week 18

Week 18 continued with more in-depth learning of Unit 4 and studying properties of atoms, molecules, and elements. Starting off the week, we did an activity in the computer lab in which we went back to Dalton's experiments with phlogiston and oxygen, and discovering the fixed ratios of elements. We came to a few conclusions in class using what we did: 2 substances with the same properties have the same ratio, the mass of a solid lost is equal to the mass of a gas produced when heating, and there are fixed ratios within systems. We moved to more about diatomic elements and how we can tell they're diatomic. Like with hydrogen chloride. If 1 vol. of hydrogen is combined with 1 vol. of chloride, but 2 volumes are produced, then you know they're diatomic elements. Then we came to some conclusions. First, we know that substances and compounds are composed of individual particles. Substances are made out of elements or pure substances. Compounds, however, are made of multiple particles that are either the same or different. Lastly, we concluded that particles combine to form molecules. To end the week, we came to our final conclusion that diatomic elements stay diatomic until they have something to combine with. We had an assessment on Friday that I feel good about, and look forward to seeing my results.