Unit Exam reflection

I was so glad that the exam was postponed to Tuesday because it gave me more time to study. I'd been studying from the weekend anyways, but the more time I get, the more confident I feel. To study for this exam, I mostly did a lot of practice problems. I used all the problems from schoology as well as from the textbook. I also used some external resources (listen in Stoichiometry summary post). I am trying my hardest on this unit exam because it is our last chance to raise grades before the final exam. I also know I need to learn this unit well because I'm sure that we will be using this for the remainder of the course. I can tell that things are only getting harder from here.

Stoichiometry Summary

I thought this unit was pretty simple in comparison to the last few units because this unit was more of an application of all the previous knowledge that we had and really the only new things we learned were the processes to solve certain problems. All the problems mostly consisted of the same basic process of starting with a balanced equation and went from converting to moles, to using the balanced equation ratio and then converting back to grams if necessary.

We can use the above process to find the mass or moles of any reactant or product in the balanced chemical equation if we are given a mass of a product or reactant to begin with. 

Example: What number of moles of O2 would be produced by the decomposition of 13 grams of water.

More practice: 

• http://www.chemistry.wustl.edu/~coursedev/Online%20tutorials/Plink/Stoichiometry/stoichset.htm
• http://science.widener.edu/svb/tutorial/genstoichiometrycsn7.html

Limiting Reagent

Limiting reagent- the reactant that is completely used up when a reaction is run to completion

To find the limiting reagent we can run both reactions to find the amount of one product and the reactant that produces the least amount of product is the limiting reagent. 

We can then use that to figure out how much product will actually be created (which will be the product created with the calculation of the limiting reagent)

Practice: 

• http://www.chemistry.wustl.edu/~coursedev/Online%20tutorials/Plink/limreag/probsetlr.htm
• helpful link that explains the concept and gives examples: http://chemwiki.ucdavis.edu/Analytical_Chemistry/Chemical_Reactions/Limiting_Reagents

Percent Yield

Theoretical yield- the maximum amount of a given product that canbe formed when the limiting reagent is comopletely consumed

Percent yield- the actual yield of a product as the percentage of the theoretical yield

Practice: 

• http://tmlimitingreagents.weebly.com/percentage-yield-and-actual-yield-practice-problems.html

Copper (II) Chloride and Iron lab

I felt pretty confident with the pre-lab quiz for this unit. Actually, when I was solving the problem I was kind of scared but that was because it was pretty easy and straightforward. It was very similar to a lot of the problems on the weekly quiz so I thought the pre-lab quiz was another great opportunity to practice for the unit exam.

 When we poured the water into the CuCl2 it kind of changed colors which was really cool. Then, when we put the iron nail into the solution, we immediately saw a color change in the nail which was cool because we could already see the reaction taking place.

When we came in for the second day of the lab, there was a dramatic change and that really helped me see the chemical reaction occurring. The process for the second day of the lab was very tedious and we had to be really careful not to pour out copper when we were trying to take the water and the hydrochloric acid out of the solution. However, I understand why it is so important to not wash away any of the copper because the final mass is what will help us determine the charge of the iron that reacted with the chloride. If we wash away too much of the copper on accident, we will get a smaller mass which will give us a different percent yield which will indicate the incorrect charge of the iron.

Weekly Quiz 12/8

I thought this quiz was deceptively simple. I felt like all the problems were really similar, which I know Mrs. Frankenberg said that the processes in this unit are all very similar and have the same basic approach but it still worried me. I think I understand this unit better because I understand the calculations we are making and why we use the certain processes and methods. The math in this unit is also a lot simpler but I can see how we're connecting all the information from all the previous units. Whenever we are told that we will be tested on any of the past units I always panic but now I see how every unit uses knowledge from previous units and we're tested on those anyways. Finally, I'm concerned for how long I took to take this quiz because it took me a good portion of the class to actually complete the quiz so I hope I will be prepared enough to finish the Unit exam in time.

Metals Lab

For this pre-lab quiz, I was confused at first because of the wording of the question because we hadn't really talked about those kinds of problems in class before. However, we already knew the answer, I just didn't realize how simple it actually was. The lab was also really cool because some of the reactions were really noticeable and had really weird reactions. Again, it was a good hands on experience for actually seeing the actual application of what we'd been learning in class. This lab was also not as long as the last two labs which is always a good thing so we didn't have to rush so I was actually able to enjoy this lab and thoroughly observe it without being rushed. After the lab, calculating the net ionic reactions was also really good practice and it definitely helped me because before I started, I had no idea what I was doing, but towards the end I was pretty confident in what I was doing. 

Quiz Reflection

I studied pretty hard for this quiz because I didn't do so great on the last few tests/quizzes and I need to even that out. However, I feel more confident on this unit in general. I think it's more of applications of what we've already learned and that makes me comfortable because it's strengthening my skills in previous units as well (like the nomenclature unit). So far, I think the hardest part of this unit has been memorizing the solubility rules and such and balancing equations. I am really bad at memorizing things (basically I don't even have a memory) so I need to work on memorizing all the rules with this unit. After getting the quiz back, I found that I have a decent grasp on the material so far and hopefully that will prove to carry throughout the unit.

Solubility Rules Lab

This lab was really cool because we got to actually see the chemical reactions occur. The reactions were very interesting and some were really noticeable. (As you can see from some of the pictures from below). I think the hardest part of this lab was keeping track of which well contained which reaction. To fix that problem, I drew out little "maps" of the well plate and wrote down the reactions on a piece of paper. It was also really tedious because there were a lot of reactions that we had to go through. We also had to clean out the well plates after each time it was full which took even more time and was tedious. Because of all these processes, it took us a really long and we ran over time. However, this lab was good practice if we predicted the driving forces ahead of time. 

Driving Forces in a Chemical Reaction

Driving Forces in a Chemical Reaction

• chemical changes are a result of chemical reactions
• reactions involve a change in energy 
• two compounds will react if there is at least one driving force present

Double Replacement Reactions

• two compounds produce two new compounds 
• the positive ions replace each other
• must both be ionic compounds that are aqueous 

Predicting the product practice: 

• this link is extremely helpful (it includes videos and a really clear procedural notes)
• here are some practice problems

Chemical Reactions and Balancing

Clues that a Chemical Reaction has occurred

• the color changes
• a solid forms (precipitate)
• bubbles form (only for aqueous solutions)
• Heat and/or a flame is produced or hear is absorbed (heat=Enthalpy)

Anatomy of Chemical Equations

Combustion- CHO method

• always reacts with oxygen O2
• combustion of a hydrocarbon always produces carbon dioxide CO2 and water H2O
• 1st Carbon
• 2nd Hydrogen
• 3rd Oxygen

Balancing Chemical Reactions

• here is a link that helps on the process of balancing equations
• here is a link for a practice quiz 
• here is a game for more practice

Unit Test

Studying:
For this Unit what I really need to do is do A LOT of practice problems. I think another thing that will help me is reading through the textbook and taking notes along the way. That way, I get the definitions down so I don't get confused between terms. Then, I can do the practice problems in the textbook to go along with the material I read. Hopefully practice will make perfect.


Reflection:

The Unit test was honestly terrifying. The main problem was the time we had to finish the quiz. I felt so rushed and it stressed me out. I feel like if  we had a lot more time for all of those problems, I would feel better about it. In general, I think the hardest part, material wise, was remembering the different methods for each problem since there are so many problem times that have similar yet completely different solution paths.

Formula of a Chloride lab

 This lab was really cool because there was a significant difference between the starting zinc and the end zinc chloride. It really helped us see the chemical reaction occur. However, it took a long time to wait for the HCl to evaporate and it smelled really weird too. This lab was also good practice for making the formula calculations. It also gave us a hands on application which I always learn better with. I thought the math would be really hard but it really helped me that the questions were step by step and guided me. I really like those kinds of problems because it guides me into how I should solve the problem which is always what I have trouble. However, it's scary because if you get one problem wrong, you're most likely going to get multiple wrong. It's a good thing we did this lab because I need all the practice I can get

Formula of a Hydrate lab

This lab was really cool and I'm really glad we passed the pre-lab quiz (those always stress me out)! It was cool to be able to physically see the change from the hydrate to the anhyrdide. I think this lab was helpful because I'll probably remember this material better since I had hands on experience in the lab. I think it was also really good practice for calculating the formulas of the hydrates and finding the variable n. I definitely am better at calculating those values after all the practice. Since we ran out of time in class, we didn't get to heat the hydrate multiple times. If I had to do this lab again, I would heat it more and see how much of a difference that makes.

Unit 6 Summary

Mole: 6.02*10^23 the number equal to the number of carbon atoms in exactly 12 grams of pure 12C

Steps To Solving mole Problems

• decide what the questions ask 
• write down the given info
• label all quantities

Mole problems road map

http://media.showme.com/files/28315/pictures/thumbs/492108/first_thumb1352935272.jpg

Hydrated Compounds

• contain water molecules in formula
• contribute to the crystallize structure of the compound 

Nomenclature of Hydrates

• Anhyrdride*nH2O
• CaSO4*2H2O ----> Calcium sulfate dihydrate

Calculating "n"

• find mass of dry anhydride (mass of final product-mass of test tube)
• find mass of hydrate: (mass of starting product-mass of test tube)
• Mass of Hydrate-mass of anhydride= mass of water driven off
• convert mass of water to moles 
• convert mass of anhydride to moles 
• Anhydride moles/ water moles = n

Helpful links: 

this video is kinda cheesy but definitely helpful!

this website summarizes and defines everything really clearly

Links for practice: 

http://www.chemteam.info/Mole/Determine-formula-of-hydrate.html

http://www.chemistry.wustl.edu/~coursedev/Online%20tutorials/Plink/moleskey.htm

Pre-Test

This was definitely the hardest pre-test I've taken in my life and I'm terrified for this unit. I'm pretty sure I guessed on 99% of the problems and I'll be happy if I got even one right. However, this pre-test has made me aware that I will probably need to work really hard for this unit and I plan to do just that. Hopefully, when we start learning the material all the questions will start making more sense. It seems like it involves a lot of math that I've never seen before. I really hope the unit test will prove to be easier for me and hopefully I will gain redemption at the end of the unit.

Last Meal Conversion Project Reflection

This project was really fun especially because food was involved! I think it  really played a big part in helping me understand the conversions and was great practice for the test. At first I thought it would be hard to memorize all the conversions but after having to use it so many times for this project, it became more easy to remember the exact measurements. It was also good practice for the rounding portion of this unit, which I really struggled with for a while but doing this project served as great practice. I'm glad we had this project actually because it was a nice cool off after the stressful unit test and it helped me review for the test as well! It was also interesting seeing what everyone else had made and all the recipes were so good it was hard picking who to give extra credit points to! I also had a fun time making my Oreo Pound cake!

Chapter 5

Accuracy vs Precision

http://www.uh.edu/engines/accurate-precise.jpg

Significant figures are digits with meaning contributing to its measurement resolution

Rounding: 

• you can estimate past the calibration of the measuring device
• example: round 0.1653 to the 0.001 place (answer: 0.165)

Significant Figures Rules: 

• zeros for "cosmetic" purposes are NOT significant
• zeros used to locate the decimal point is NOT significant
• Any numbers between 1 and 9 ARE significant 
• All zeros between non zero integers ARE significant
• zeros at the end of the decimal value ARE significant because it shows where you can round and the accuracy of the number (also where the measurement device is calibrated)
• all numbers in scientific notation ARE significant 

Addition and Subtraction: 

• the number of significant figures in the sum or difference are the same as the measurement with the smallest number of decimal places

Multiplication and Division: 

• the number of significant figures in the product is the same as the measurement with the least significant figures

Order of Operations:

• same as in math
• Parenthesis
• Exponents
• Multiplication
• Division
• Addition
• Subtraction

Metric Conversions: 

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_IYAFI7j7o2vXSq-8-zWeF7IsypN1dcuWMVIAKe1I9OZwsgfuVLudyYQcChG1SM2TEYwVcoqM79RatSJaCtE1Aj17FGwJTZmIQABSBSB9_pAWQipCLXExEx-O9XuN6pEQ6VCIuRE5-FE/s400/units+king+henry+died+drinking+chocolate+milk.png

Helpful Links: 

• http://www.usca.edu/chemistry/genchem/sigfig.htm
• http://chemistry.bd.psu.edu/jircitano/sigfigs.html
• http://chemistry.about.com/od/chemistryquickreview/a/accuracyprecise.htm

Practice: 

• http://www.dallassd.com/our%20schools/high%20School/Chemsite/chem/hotpot/sf.htm
• http://www.chemistrywithmsdana.org/wp-content/uploads/2012/07/SigFig.html
• Bookwork: pg 164 #1-34

Mole Day

Making the mole was a lot of fun because we were free to make it however we wanted and had minimal restrictions. This project was also less stressful and a nice reliever from the other projects. I think making the mole and having the mole day celebration helps us remember the significance in chemistry. I'll probably remember chemistry every time I see a mole or when the topic arises now. It was also fun seeing all the other moles and seeing all the creative ideas other people had. The party was fun too because it was a nice ending to the week and a nice reliever before the quiz Monday.

https://dj1hlxw0wr920.cloudfront.net/userfiles/wyzfiles/fdb688ae-ebf3-406f-adc0-879dc144e389.gif

At first I was confused as to why we were making a mole, but this link summed it up for me and it started to make more sense! 

Unit 3 Pre-test

I feel like there were some things in this pre-test that we already knew from previous classes. For example, measuring lengths and reading graduated cylinders. But I also think some questions were new but we could easily learn because they build on prior knowledge that we already have. I also struggled a little in remembering the answers for the review questions so I definitely have to go back and review so that I don't forget. I think my memory was probably rough from the break so I need to go back and simply review my notes. This unit seems pretty short and I hope I do well this unit so I can help my grade.

Unit Test Reflection

Overall I think the unit test wasn't as hard as I thought it would be. Don't get me wrong, it wasn't easy but it wasn't too bad. The night before the test, I started working on the guided readings while reading Unit 3 and 19 in the text book. When I got to Chapter 19 I realized we hadn't covered some of the topics in class and I panicked. So I thoroughly read the chapter and took the practice assessments in the schoology test prep link. Thankfully there wasn't much of Chapter 19.2 on the test but I'm really glad I read it because it gave me a better understanding of the topic as a whole. Since a lot of chemistry is linked together and knowledge that you acquire is often used in later topics; I think that having done all that will definitely help me in the long run. After I had read the chapter, I went through all the practice tests on schoology and I'm REALLY glad I did that because I found that the questions on the test had similar formats which gave me a feel for what I would be seeing. After doing the tests, I marked which problems I had trouble with and went back and reviewed that in our notes and the textbook. I really like doing practice problems before tests because I have noticed that it helps me a lot. As they say, practice makes permanent; and perfect practice makes perfect. (and that's the goal)

Star log reflection

The star log project was actually very cool and I enjoyed it a lot because astronomy has always been interesting to me. I think I even wanted to be an astronomer at one point in my life. I also think that this project was a lot less stressful than the Frontier Chemistry project because I think the first project prepared us for this one. (I'm also pretty glad we don't have to do an essay for this one) I think the information was a lot easier to find and there was less stuff we had to find. I also like how we got to pick which stars we wanted to research, I think it made it a little more exciting and unique. I think I did a better job of managing my time for this project, however if I could improve I would see if it were possible to find further information about the chemical composition of each star. I used the Harvard research base for a lot of my research but it was difficult to read through the abstracts and understand the terms that they used sometimes.


Some other useful links for this project: 
http://www.umop.net/spctelem.htm
THIS one is my personal favorite because they made easy to read charts with most of the information I needed
I also used Wikipedia a lot for background information about stars and constellations

Half Life

In this unit we learned about how to calculate half lives. Half lives are the time it takes for half of a sample of atoms to decay to a stable form. For example, in the Forensic archaeology lab, we calculated half lives of the radioactive atoms in a sample. The formula for calculating half lives is listed below. Half lives can be used to trace the amount of time a sample/remain has existed. That can be used in crime scene investigations to determine how long a person has been dead. At first, when we started this section I was actually really confused and was confused especially when we were given word problems. However, the lab that we did (the forensic archaeology lab) helped me solidify my skills.

http://www.m2c3.com/chemistry/VLI/M3_Topic2/la_06_13.jpg

Useful links:
http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/halfli.html
http://www.coolmath.com/algebra/17-exponentials-logarithms/13-radioactive-decay-decibel-levels-01

Forensic Archaeology lab

In this lab, we used paper instead of radioactive molecules to get a feel for how half life works. This lab also helped us practice calculating half life and understanding what the calculations mean and why the specific formulas are used. The formula to calculate half life is: # of radioactive atoms initially/ 2^half lives. To calculate backwards to determine the original radioactive mass from the half life mass, we use the formula # of radioactive atoms*2^half lives. After calculating the data from this sample experiment, we use the collected information to apply it to the real world problem given and use the information of half life decay to determine how old in years an artifact (body) is. I think this is a good experiment that not only helps us practice calculating half life, but we also understand how half life calculations are used in the real world. I think applying acquired knowledge from lectures to real world or hands on activities really helps me understand concepts better.

Quiz

I think I did pretty good on this quiz. This unit, I am doing slightly better because I am getting more used to this class and getting more accustomed to how to study. This unit seems to consist more of the math skills that Chemistry is known for. I hope to do well in this unit because math is one of my strengths. This quiz reflects my understanding so far in this unit and I feel like I have a pretty good understanding of the material so far. I was also able to raise some of my grades in the previous objectives in the nomenclature unit. I am glad that I still remember that unit because I know that is a very important part of chemistry/this class. To prepare for the upcoming unit test, I need to practice with practice problems from schoology and from the textbook. That is how I studied for this quiz and I think it really helped. Therefore, I plan on using this study method more often.

Mass of Subatomic Particles

In today's lesson, we learned about masses of subatomic particles. First, we learned the labels of an element in a periodic table because that is what we use to determine a lot of things in this unit. (see picture below). The letters in the middle are the Element symbol, the name below is the element name, the number at the top is the atomic number (the number of protons and electrons), and the number at the bottom (usually a decimal) is the average atomic mass. Then we leaned the notation for recording different isotopes of an element. Which is done by using the element symbol and two numbers on the right (see picture below). The number on the top is the mass number and the number on the bottom is the atomic number (number of protons/electrons). The number of neutrons can be determined by subtracting the atomic mass by the number of protons. Then, we learned about calculating average masses and percent abundances of isotopes. The formula for calculating average atomic mass is (mass of one isotope)*(% abundance)+(mass of other isotope)*(%isotope). This same formula can be used to figure percent abundances when average mass and isotope masses are known.

Element on periodic table labels

picture

Isotope notation

picture

Extra resources:
calculating practice: http://www.chemteam.info/Mole/AverageAtomicWeight.html
http://blog.wsd.net/hewaite/2014/10/ 
http://ehschemcorner.blogspot.com/2012/09/the-atom-isotopic-notation.html 

Atomic Theory and Nuclear Chemistry

The notes that we took today seemed more informational than the last unit. The last unit felt like it was more of application of rules. Today, we took notes on Dalton's Atomic Theory, Law of Constant Composition, JJ Thomson, Rutherford's Gold Foil Experiment and the current Atomic Model (the cloud model). To remember each of these scientist's discoveries and importance, my friends in other chemistry classes made acronyms. Knowing those acronyms, its already easier for me to remember these scientist's roles than it would have been if I had just tried to memorize them today. The activity that we did at the end of the notes (the obscur-tainer lab) today was also fun. There was a small black dish with a shape inside and a small metal ball; and we had to roll the ball around to guess what the shape was inside. This kind of relates to how Rutherford did his Gold Foil Experiment because he used other elements (ex: the metal ball) to bounce off the gold (the shapes) to figure out unknown properties of Gold.

Gold Foil Experiment (Rutherford)

http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_04/FG04_04.JPG

Thomson's Cathode Ray experiment

                                                                                                                               http://www.physicsoftheuniverse.com/topics_quantum_atomic.html

Extra resource:
https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/atoms-molecules-and-ions-2/history-of-atomic-structure-32/john-dalton-and-atomic-theory-197-6138/
http://www.physicsoftheuniverse.com/topics_quantum_atomic.html

Unit 2 Pre-test

The pre-test that we took on Tuesday was really difficult. I didn't know the majority of the answers. However, on some of the questions, I was able to use prior knowledge of chemistry to make an educated guess. Also, as I continued I recognized that there was probably a pattern in the questions with the atomic masses and etc. The test also included sections where I had to read and answer questions about graphs which wasn't as hard as the rest of the test because we were able to use prior skills of reading scientific graphs.

Frontier Chemistry Reflection

I really enjoyed this project regardless of how stressful it was because it was an interesting real world application that we often look for when learning in school. Now, every time we go out I notice these plants that we have been identifying for this project and it makes me feel like I have learned something in school that I can actually use in the real world. Now, if I AM put in an emergency situation like this out in nature, I can use these skills and information I learned to help someone who is hurt. We also started identifying the active chemical ingredients in these plants so maybe when we come upon these ingredients in the future in the class we can identify what these ingredients may act against. This project required a lot of research and I had to know what sources were credible and I had to know how to find the information I was looking for. This was even harder because you couldn't just google the information and find it as one of the first few results. It took me a while to figure out how to find the information I need quickly and effect-fully. So, if I had to do this project again I might be able to find my information faster and be able to find credible sources.

Unit 1 Reflection post

From Unit One I learned how to read the periodic table of elements which helps you name compounds, acids, and polyatomic ions which was the main focus of this unit. At first, when I took the pre-test I had no idea what I was doing. However, the next day we started learning about the material and it started making sense. I really like this unit because even though it seemed like a lot that we were taking in at a really fast pace, as we moved on, we made our knowledge of the previous information stronger. Memorizing the polyatomics was probably one of the hardest parts but I used quizlet to name the compounds by looking at the chemical structure at first. Then, when I had mastered that, I moved on to labeling the chemical structure by looking at the name. As I moved on, it started making logical sense (such as when -ite and -ate was used) and it became easier and I was able to identify them faster. Then, when we learned naming acids, it was simple and quick to learn because we had a strong base of all the other topics and it was just a matter of application.

Introduction Page

Chemistry: I have chosen to take Honors Chemistry this year as a sophomore because I wanted to take the Pre-AP version early so I can see if I want to continue to take AP Chem in the future. My goals for this class is to pass all the objectives with a mastery grade and pass with a final A. 

About me: I like to play tennis and I am on the varsity tennis team this year. I also love photography and I'm a photographer for the yearbook publications here.