Test Prep

While I may not even be there for the test- I'm still studying during the short period of time I have enough energy to. So here's some resources to review all of stoichiometry:

Limiting Reagents and Percent Yield
Explanation + examples
Walk through Video

Also do the worksheets on schoology!

Percent Yield

Last thing we learned in this Unit was percent yield:

Actual Yield / Theoretical Yield x 100 = % Yield

Doing this as another step to Stoichiometry can be a bit confusing. Here's some resources to help:

Percent and Theoretical 
Info + walk through of Problem
Limiting Reagent and percent yield

Lab. So Far

I haven't been here for most of the lab but so far what I've seen is that we're making solid copper in a baby food jar using a nail. Single Replacement reaction: Copper II Chloride + Iron = Iron II Chloride +Copper. On the day I was there we-

Washed off the remainder of the nail
Siphoned off the solution of Iron II Chloride
Washed copper with HCl and distilled water
Put copper in 'drying oven'

Nail in baby food jar

Washing the Copper

Copper 

Quiz

Oh boy. I feel like that was way harder than it should have been. I've had an easy time learning this yet I didn't do very well on the test. I don't mind making connections between what I've learned and harder questions but to do it on a test with limited time worth a huge amount of points is very nerve wracking. Trying to find a way around this confusion still.

Some study links for people who didn't take it yesterday for some reason:
Stoichiometry 1
2- Video
LOTS of links and resources

Example of how to set up the problems - Source

End of unit

Chemical Reactions- Source

Well I feel like I didn't have that hard of a time understanding this unit, but I'm still struggling with the tests. I'm really not sure how to improve on tests because I know I understand it and I study a lot so I'm not sure. Anyway, not a horrible section. Less math the better.

Writing Equations

Molecular equation is the complete reaction formula

Ionic equation is the broken down formula (Only things that are ionic get broken down- ex:solids do not get broken down)

Net Ionic equation is the driving force. (Ionic minus the 'spectator ions'- ions not used to produce the driving force.)

Links: Net ionic Info

More thoughts on reactions

Still working to understand a bit more about the reactions:

The types of reactions are:

Redox

Double-replacement 

Acid-Base.

There are different types of Redox Reactions:

Synthesis A+B = AB

Single replacement  AB+C+AC+B

Decomposition AB=A+B
Combustion A+B+02= AB

Redox reaction's driving force is the transfer of elections.

Double replacement's driving force is the solid produced.

Acid-Base's driving force is the production of water. 

Resources: 

Different types- Video  / Web

Source

Redox Lab

Passed the prelab quiz! This lab was really cool. Basically we were testing oxidation rules in redox reactions by combining elemental solids and aqueous compounds and then writing down whether a chemical reaction occurred or not. These reactions took a little while but overall they were super cool to see! Afterwards we created a reactivity series based on our data. We also wrote all the net ionic equations for our reactions which helped me understand redox reactions much more through repetition.
Oxidation rules
Oxidation numbers
Agents

Our reactions as they were reacting!

Our reactions once they were finished reacting

Test Prep

Overall, I feel pretty okay for this test. Not that that means much. I think the thing I have trouble with is telling the difference in the types of reactions. There was so much information in this one section that it's blurring together. Hopefully I can pull it together. Some helpful resources:

Video on Redox: Linda Hanson
Balancing: ErhsChem
Acid-base Reactions: Crash Course
Double-replacement reactions: GetChemistryHelp

Final test thoughts

Well I got an 81 so I guess it wasn't too bad. Still hoping I'll be a bit more prepared for tests in the future. On to chemical reactions! 

Solubility lab

This week we completed the solubility lab. I passed the pre-lab quiz so I was able to get started right away. Basically we had a chart of certain chemicals & mixed them together in a palette to determine whether they have a driving force or not. I predicted the entire chart the night before by working out each equation. This made it a lot easier to complete all the ionic formulas as I only had to redo the ones with an unexpected result. My favorites in this lab were the reactions that turned vibrant colors.

Our palette of reactions!

Such as the yellow one here. 

Test thoughts

It was hard. I can't think or do math that fast. Here's how I feel inside:

Chloride lab

This week we completed the Chloride  lab.

In this lab we measured a dry 100 mL beaker to the nearest 0.001 g and record this mass in the data table.

Then we placed a small amount of zinc into the beaker and determined the mass of the beaker + zinc and recorded it in the data table.

We added10 mL of 3M HCl.  With a hot plate, we heated the mixture until all of the zinc has dissolved.

We continued heating the solution until all of the water and excess HCl have been boiled away. We stopped heating after the last bit of liquid was gone and the solid formed 

Lastly we let it cool for several minutes and then determined the mass of the beaker and contents. 

As post lab we found the formula for the salt 

Here are some links to the lessons reinforced in the lab 

Empirical and molecular formula 

Empirical and molecular practice problems

Empirical vs. Molecular formulas

First Chemical Composition Lessons

I'm actually so surprised at how well I'm understanding these lessons. I've done well on all the activities so far, and seem to be doing everything correctly. I hope this continues!

Here's some links regarding what we're doing:

Mole Conversion 

About Moles

Molar Mass

Chemical Composition Pre-Test

Wow, I knew absolutely nothing on that pre-test. I gave up on about the third problem and just filled in B. Hopefully things will start getting easier.

Matter and Measurement Unit Exam

Well considering I did very well on the quiz- I'm shocked to see that I did not do as well on the test. I didn't think it was too hard but what can ya do. Such is life. More studying next time.

Matter and Measurement quiz

We took a quiz on Monday over the things we leaned so far regarding matter and measurement, it wasn't too bad as long as you looked over your class notes. I'm pretty nervous about the unit test though, here's some things to study:

Metric Conversions

How to convert metrics

Sigfigs

Accuracy v. Precision

More conversion

More sig figs

Mole Party

Our mole party went great! Everyone's moles were so cute! It was a good break- but onto the next thing as always. Happy Mole Day!

Source

Source

Ther 'Mole' Vision

This week I made a cute mole! ... like the animal. I wish I had pictures but they got deleted whoops. Anyway, I made it out of felt. The feet were tan colored, and the body was brown. I made little thermal goggles for him out of grey and green felt. His tail and nose were tan pom poms. Did it for the pun.

Source

Aspirin Lab

This week some of our class did the Aspirin lab. I didn't get to do the lab though, despite memorizing the entire lab packet. Since I did that I'm going to make a blog post about the lab, with data and pictures from the wonderful Meg Tersteeg's lab.

Cutting out filter paper in preparation

1st day of lab:

First you use a weigh boat to measure out 5.00g of Salicylic acid (C7H603 ). Then you transfer it to a 125mL Erlenmeyer flask.
Record this starting mass: 5.1444g

Weigh boat

Then bring the flask under the hood and have 7.00mL of acetic anhydride ( C4H603 ) delivered to the flask. It is important to not let the acetic anhydride to contact your skin or let the vapor get in your eyes, as it is a dangerous acid.

Now add 8 drops of the catalyst, Sulfuric Acid (H2SO4).

Next you heat the starting materials:

Assemble a hot water bath using with a 400, 600, or 800 mL beaker. Do this at your lab bench and place the flask in it. Heat till boiling + an additional 15 minutes

Heating the flask

Lastly for day one, you cool the mixture.

Allow flask to sit on lab bench to cool for about 15 minutes

After, add 15mL of ice cold water to decompose the excess anhydride.

Place flask in ice bath till crystallization of aspirin is complete.

Day two:

Isolate the product-

Collect the solid aspirin using a Buchner funnel and filter paper. Rinse flask twice with 3mL of ice cold water to remove any residual crystals.

Discard leftover filtrate in waste container under the hood.

Buchner funnel set up

Rinsing flask with ice cold deionized water

Lastly in the lab you dry the product by suction filtration.

Dry the crystal by pulling air through them for 15 minutes.

Finished, dried product.

I chose to write about the lab procedure instead of the significance of the lab because I did not get to participate in the lab.

The Day the Stars Went Out

Finally done with the star project. I actually enjoyed it very much, learning about lots of stars and their history was really interesting. Excited for the new unit though, wasn't incredibly fond of this one. 

Helpful star log links: 

http://www.universetoday.com/45775/famous-stars/

http://www.astronoo.com/en/stars.html

http://www.astronoo.com/en/brightest-stars.html

Atomic Structure and Radioactive decay chapter 19

Today we learned about Radioactive Decay. One type of radioactive decay is Alpha particle decay. These are helium nuclei 24He. The mass changed by 4 and the protons change by 2 from parent atom to daughter atom. We also learned about beta particles which are electrons in which the mass does not change and the proton changes by one between the parent atom and the daughter atom. Gamma decay is always there accompanied by either alpha or beta decay.

More info: http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch23/modes.php

Atomic Structure and Radioactive Decay Chapter 3 quiz

Chapter 3 Quiz was relatively easy as long as you knew who was who. Some of the questions made me second guess a lot thought, which I dislike. Questions that you genuinely feel like you have no idea how you could even know the right answer are so frustrating. But other than that, the quiz was easy and I'm happy with the results. On to chapter 19!

Atomic Structure and Radioactivity Day 1

9. 16.15

Today we learned about Dalton's Atomic Theory. Dalton was the first to discover subatomic particles. He did not know of subatomic particles. Some of his theories have been proven wrong, but some are still true and fundamental (Ex. All elements are composed of atoms.) Another thing talked about was the Law of Constant Composition, which tells us that a given compound always contains the same Proportion by Mass (Percent Composition.) Another scientist, JJ Thomson, found the subatomic particle, electron, with a negative charge.He used the "Chocolate Chip Model" - Electrons placed randomly in a positive matrix. Ruthford, a student of Thomson, discovered positively charged protons by the Gold Foil experiment.  He also found the nucleus, a small and dense area containing protons.

More info: http://www.iun.edu/~cpanhd/C101webnotes/composition/dalton.html

First look at Atomic Structure and Radioactivity

    The pretest for Atomic Structure and Radioactivity was undoubtedly hard, I was able to figure out some patterns within the questions, but mostly it was foreign to me. It's hard to imagine that these things will soon be incredibly familiar to me.  Not totally looking forward to the whole math aspect of it, but I'll get used to it.

More info: http://science.howstuffworks.com/nuclear-bomb1.htm

Hardest part of the Nomenclature Unit

The hardest part of the Nomenclature unit was memorizing the polyatomic ions. These ions have no set naming system so I had to memorize each one and their charge individually.

More info: http://www2.pvc.maricopa.edu/tutor/chem/chem130/nomenclature/polyatomicion.html

Main things I learned in the Nomenclature Unit

      In the Nomenclature Unit, I learned different types of chemical compounds and the system to name each type. Most types include a metal and a non-metal except Type III compounds, which contain two non-metals. Polyatomic ions are special compounds that are composed of two or more atoms and do not have a special naming system. Acids are compounds with Hydrogen attached. I learned how to name Type I, Type II, Type III, and Acid compounds.

More info: http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch2/names.html

Introduction Page

I'm Aly, I go to Francis Howell and I'm in 5th hour Pre-AP Chem. I'm in theatre and that's about all I do.