RedOx Reactions! Yikes!

Today we were introduced to another type of reactions in which the driving force is the transfer of electrons. Personally, I do not think that these redox reaction are any harder than the other types that we have learned.The only thing that it a little frustrating is that we have another set of rules to memorize in a day. I will provide a acronym to go along with the rules to help memorize them.

Redox Reactions:

http://sites.saschina.org/sabrinapx2016/files/2014/10/05-02_RedoxReactions_L-1lpckw6.jpg

General Overview of Today's lesson:

 

• Oil Rig- Oxidation is loosing; Reduction is gaining (in terms of electrons)
• +2 (oxidation state) 2+ (charge)
• If water reacts with an element in a problem, write water as HOH

In a Redox Reaction:

• the metal replaces the metal or the non-metal replaces the non-metal depending on what type of element is free 
• aka single replacement reaction
• reaction based on reactivity series; the element replacing the other in the compound be higher on the reactivity series in order for it to react

 

Example Problem
2Al(s) + 3I2(s) -----> 2AlI3(s)

• 2Al(s) has a state of 0
• 3I2(s) has a state of 0
• 2AlI3- 2Al has a state of +3 and I3 has a state of -1
• that means Al lost reactions making it positive which means it was oxidized or the reducing agent
• Iodine gained electrons making it negative which means it was reduced or the oxidation agent

Hopefully I will understand this well enough for the pre-lab quiz tomorrow because the lab sounds like it will be extremely interesting and I hope to be able to participate.

Oxidation Rules

Overall, today was not terribly hard by any means. I just have to memorize all the rules and I will be just fine.

Redox Reactions (video)

Quiz yourself
Redox Reactions

My thoughts on the Quiz

Personally, I had mixed feelings about the quiz. I felt the topics that were covered on the quiz were very easy topics to understand and I felt extremely prepared. However, many questions were much harder than the problems we did in class or were assigned for practice problems. I was pretty frustrated with that aspect of the test. In addition to that, I also have mixed feelings on the length of the test. This one was only 11 questions which makes me feel better, but we still had a time limit and if we missed one it already set us back a fair about of percentage points. I felt like I knew the information well enough, so let's just hope my grade reflects it.

http://www.middlebury.edu/system/files/media/question-mark.jpg

Solubility Lab

Lab on Solubility

I was extremely nervous for this pre-lab quiz because I was not present for the lesson the day before and the quiz was basically a test of your knowledge of solubility rules and what they had just learned. I had to study a lot last night and it payed off because both Liesel and I passed the pre-lab and got to go back and do the lab!

Overall the lab was simple and easy to follow. We had a chart of many different compounds and we had to cause a reactions between two of the compounds every time until we did all the possibly reactions. Basically we dropped a some of one chemical into the well and then added the other one and looked to see if a precipitate formed. It was fairly noticeable when a participate formed because it either changed color, had an obvious solid in the liquid, or became cloudy.
It was a fun and interesting lab to see whether or not your work of all the equations was correct since we had to predict whether or not a solid would form.

If you are confused on what we did in lab today, here is a video that explains it a little more:
Solubility Lab

Overview of Today

Today we covered some small topics and some big topics: symbols of a chemical reaction and double replacement reactions

Symbols: We have to understand and memorize what these symbols mean because it will be important later on in this chapter. We are already using many of them in our work.

http://honors-chemistry.wikispaces.com/file/view/symbols.jpg/142975589/symbols.jpg

Double Replacement Reactions:
In a very broad general sense, double replacement reactions are:
AB(aq) + CD (aq) ----> AD (aq or s) + CB (aq or s)

To figure out if the products are aqueous or solid you use your solubility rules. There are many tricks and acronyms to memorize them which I will include below.

http://tse1.mm.bing.net/th?&id=OIP.Md9e9add651984c67f165ba6aefbec7f5H0&w=300&h=300&c=0&pid=1.9&rs=0&p=0

Overall, today was not terribly hard by any means. I just have to memorize all the rules and I will be just fine.

Double Replacement Reactions (website) (video)
Solubility Rules (website) (video)

Quiz yourself
Double Replacement Reactions
Solubility Rules

Ready... Set..... React!

Today was the start of our chemical reaction unit. I am very excited for this unit because it seems like it will not be as bad as the last one.
We started off today talking about what a chemical reaction is a signs to look for:

1. color change
2. a solid forms
3. bubbles form
4. heat and/or a flame is produces, or heat is absorbed
• exothermic (gets hot)- energy leaves the reaction (-)
• Energy is written as a product
• endothermic (gets cold)- energy goes into the reaction (+)
• Energy is written as a reactant

http://tse1.mm.bing.net/th?&id=OIP.M1faf5a1217683b916480eb4d41bc312fH0&w=300&h=300&c=0&pid=1.9&rs=0&p=0

After we figured out whether a reaction was chemical or not, we had to figure out the chemical equation.
EX: CH₄(g) + 2O₂ (g) --> CO₂(g) + 2H₂O(g)

•  CH₄(g) + 2O₂ (g) = reactant
• CO₂(g) + 2H₂O(g) = product
• --> = yields sign
• (g) = state of reactant/product

When writing the equation you must make sure all the atoms on the left side are the arrow are balanced on the right side of the arrow.

CH₄ + O₂ ---> CO₂ + H₂O

 This Chemical equation is not balanced! What do we do?

***********Start with the CHO method (Carbon-Hydrogen-Oxygen)**********

Looking at the carbon: 1=reactant; 1= product (we dont have to change anything there since they are balanced)

Looking at the Hydrogen: 4= reactant; 2=product (we would have to add a coeffiecnt of 2 in front of the H on the product side to balance it on both sides, leave 4=reactant; 4=product)

Lastly, Looking at the Oxygen: 2=product 4=product since there is 2 oxygen in CO2 and with the added coeffient for Hydrogen the 2 is distributed to the oxygen which adds two more (we would have to had a coeffient of 2 to the O2 on the reactant side to balance the equation)

Leaving us with an equation of:

CH₄ + 2O₂ ---> CO₂ + 2H₂O

We also learned about combustion. Three main things you should know:

1. always react with oxygen
2. combustion of a hydrocarbon always produces carbon dioxide and water
3. Use CHO method when balancing

If you need help with anything from above there are links below to videos/websites that might help:
Chemical vs Physical Reactions (website) (video)
Balancing Chemical Equations (website) (video)

Quiz Yourself:
Chemical vs Physical Change Quiz
Balancing Equations

Reaction Series Lab

In today's lab we observed reactions between metals and chemicals to see where each metal would land on the reactivity series. Calcium was very reactive and on every chemical added, it fizzes, bubbled, smoked, and turned a different color. This was one of my favorite labs we have done so far.

Formula of a Chloride Lab

(At the end of the post there are two links that lead to to websites/videos that can help you understand the lab or how to calculate the answer)

(Sorry my pictures are out of order a little bit, Blogger does not let me position them the way I would like. I tried to label them as best I could)

The first thing we had to do today in order to do the lab was answer the pre-lab questions correctly. I was really nervous for these pre-labs because I was trying to calculate the practice questions and I was getting very confused. Personally, I felt like they were different than the ones we did in class. After the question came on the screen, I felt better about solving it. Fortunately, I correctly solved the question and my partner and I were able to go to lab!

 INTO LAB WE GO!

Today our general procedure (pictures included at the end) was to: 

1. Find the mass of a dry 100 mL beaker.

2. Place a piece of zinc into the beaker.

3. Determine mass of beaker plus zinc.

4. Add 10 mL of 3M HCL into the beaker.

5. Gently heat mixture on a hot plate until all of the zinc had dissolved and the water boiled away. (you should be left with a salt)

6. Heat substance for 5-10 minutes (or until it turns white) on high 

7. Cool for a couple minutes.
8. Find the mass of the beaker and its contents.

3M HCL

Zinc Dissoving

Starting to boil

Zinc in Beaker

Pouring 

Boiling

Dissolved Zinc

Final product of Salt

Cooling the Substance

Our Data and What is Means

Data Table and Calculations of the Amount of Zinc and Chlorine in the Salt

Calculation to find the Empirical Formula

For those that were unable to complete the lab here is a link to a video of what we did:Formula of a Chloride Lab (keep in mind that we used different measurements)
If you are having trouble calculating empirical formulas, here is a link to a video to help you understand the steps and to take a quiz to test your knowledge: Internet Science Room or ChemTeam

Today's Quiz

I felt so ready for this quiz today. I studied my notes, did practice problems, found quizzes online, and knew my polynomials; however, after taking the test, I am extremely frustrated because I got confused on some of the problems. I knew how to do everything we did in class, yet I still feel like I didn't do well on the quiz. Everyone else thought it was easy which discourages me even more. This class can be very rewarding, but it also can be very frustrating
and annoying. Hopefully my grade on this test isn't as bad as I think it will be.

http://www.livryan.com/wp-content/uploads/2015/04/crying-emoji.png

Formula of a Hydrate Lab

Fun Fact about today: We got candy in our phone slots! Yum!

Before and After

CuSO4

(At the end of the post there are two links that lead to to websites/videos that can help you understand the lab or how to calculate "n" in a formula)

The first thing we had to do today in order to do the lab was answer the pre-lab questions correctly. We picked one partner to be A and the other to be B. We then were told the questions. I was lucky and got to answer the quick question about the general procedure, while my partner had to complete the math portion. I ended up doing the math part anyway just for more practice. 

WE BOTH PASSED! INTO LAB WE GO!

Heating test tube

Today our general procedure (pictures included at the end) was to: 

1. Find the mass of the dry test tube

2. Fill it with 2 cm of CuSO4

3. Find the mass of test tube and CuSO4

4. Put test tube on a ring stand

5. Heat substance for 1-2 minutes on low heat with a bunson burner.

6. Heat substance for 5-10 minutes (or until it turns white) on high 

7. Remove and cool

8. Find Mass of test tube and substance

9. Reheat 3-5 minutes

10. Re-cool

11. Re-weigh

12. Repeat until water driven off

13. Clean test tube

While Heating, Condensation can form on the top of the test tube

Overhead view of the Test tube and its contents

Things with our experiment specifically:

After we had gotten the mass of the test tube with the CuSO4 in it, we wet back to our station. While preparing to put it on the ring stand, I unfortunately, wasn't thinking, and turned a page in my packet with the test tube in hand. What did this mean? I dumped the CuSO4 all over the floor. Yikes! I called Mrs. Frankenberg over and she told us to just go refill our test tube. I felt so bad! At least I learned from my mistakes.

Secondly, when we were heating the CuSO4 we began to smell the gas coming from the test tube so we had to stop heating and let it cool even though there were blue crystals left. By the end, we had gotten rid of any blue crystals but we had a few that looked green and others purple. Hopefully we did this right. Our teacher said it looked good to her, so I hope that means we did good!

Our Data and What is Means

The Data Collected

My math to Find "n"

For those that were unable to complete the lab here is a link to a video of what we did:Formula of a Hydrate Lab
If you are having trouble calculating "n", here is a link to a video to help you understand the steps and to take a quiz to test your knowledge: Study.com

Measuring Aspirin Product

We got to use our knowledge of converting grams to moles into practice through our aspirin lab. First, we had to finish getting all the of the measurements that we needed. The only one that we had left to weigh was the dried Acetylsalicylic acid (the crystals that we let to dry during break). We trasferred the crystals to the balance and weighed the substance. Our group got 5.4766g of substance which included the mass of the filter paper. Mrs. Frankenberg then told us that we need to convert our starting material and ending material's masses into moles. Using everything we had learned the last few days, I was able to complete this assignment without trouble. My work is shown below:

http://vignette2.wikia.nocookie.net/sciencemadness/images/2/21/Acetylsalicylic_acid.JPG/revision/latest?cb=20140919033453

Molar Mass of Salicylic Acid (C₇H₆O₃):

(7*12.01)+(6*1.01)+(3*16.00)=138.13 g/mol C₇H₆O₃

Salicylic Acid in Moles:

5.1444g C₇H₆O₃ x (1 mole C₇H₆O₃/138.13 g C₇H₆O₃) = .037243 moles C₇H₆O₃

Mass of Acetylsalicylic Acid:

5.4766g (Acetylsalicylic Acid + filterpater)- .4074g (filter paper)= 5.0692g Acetylsalicylic Acid

Molar Mass of Acetylsalicylic Acid (C₉H₈O₄):

(9*12.01)+(8*1.01)+(4*16.00)=180.17 g/mol C₉H₈O₄

Acetylsalicylic Acid in Moles:

5.0692g C₉H₈O₄ x (1 mole C₉H₈O₄/180.17g C₉H₈O₄)=.028135 moles C₉H₈O₄

I checked my work using this website: Endmemo