Last week we began the Copper Lab that involved reacting together iron (in the form of a nail) and copper chloride. We first had to take the mass of both the baby jar and the nail, then add the copper chloride to the jar. Then we polished the nail and added it to the jar. Almost immediately the reaction began to take place and copper started to form. We set it aside for the weekend and will address it this week.
This method was a life saver for me and I hope they can help some other people. It basically transforms stoichiometry into one large algebra problem. These links really helped me! http://ed.ted.com/on/uHuxtp3w
Yesterday we completed the copper lab, which reinforced our understanding of chemical reactions and their composition. When we combined iron with copper chloride, we produced an ugly solid copper. These labs really help me picture the reactions and makes it easier to calculate and determine answers.
I felt very confident while taking this quiz; however, my score suggested that I need to study more for the exam. I am still struggling with determining the limiting reactant and excess amounts. These links really helped me study and practice more.
This week we completed another lab relating to chemical reactions and their equations. In this lab, we reacted we metals with water, hydrochloric acid, silver nitrate and copper sulfate and determined if a chemical reaction had occurred. The four major signs that a reaction has taken place are a change in color, formation of bubbles, heat and / or flame is produced or a solid is formed. This lab helped me visualizes all the rules and reactions we have been studying and also aided in preparation for the test.
I missed the lecture in class today, but from what I can gather, it involved the driving forces of chemical equations, which are the formation of a solid, water or gas or the transfer of electrons. A chemical reaction involves a change in energy and will only occur if a driving force is present. Each occurs in a certain reaction, such as the formation of a solid (precipitate) occurs in a double replacement reaction and the formation of water occurs in either an acid-base neutralization reaction or combustion. I also used these resources to fill in the gaps of the notes.
Today we took our weekly quiz, which always stresses me out. I studied rigorously for it, which might be overkill for a simple quiz, but I can not do badly on this. I consulted many friends and resources while studying and used a variety of outside sources to aid in my learning. Some of the sources I used were:
Today in class we had a lecture over Ch 7, which includes chemical reactions, their characteristics and balancing equations. I found this lesson relatively straightforward, with just a few new pieces of information. For example, the difference between a change in subscripts and coefficients was finally made clear to me. A change in coefficient changes the amount of molecules, while a change in subscript completely changes the composition and identity of an element. It is extremely important to not confuse the two and to understand when both changes are appropriate. Additionally, I learned the importance of combustion and how to balance an equation using the CHO method. Combustion always reacts with oxygen and always produces carbon dioxide and water. Also, to balance its equation, it is easiest to start with carbon, then work on the hydrogen and finally end with the oxygen.
In the beginning of the unit, we participated in a lab to test our knowledge and prediction of solubility rules. To guess which reactions would actually occur, we combined compounds and carried out double replacement reactions. There were approximately 12 reactions that actually took place which then required us to form their net ionic equations. This real life practice helped me envision the lecture and its information.
