Copper (II) Chloride and Iron Lab

Today in class we started the Copper (II) and Iron Lab! To pass the prelab, we had to answer a basic stoichiometry problem correctly.

All we did for the first day was first weigh an empty baby food jar, a nail scratched with steel wool, and copper (II) chloride.

We added water and the copper chloride to the jar, stirred till it dissolved, and added the nail.

Here are some pictures of the process:

Now we will wait two days for the copper chloride to react with the nail. 

Percent Yield

To find the percent yield, things are actually pretty easy!

All you have to do is take the actual yield divided by the theoretical yield and multiply that by 100.

I remember this because anything actual comes over anything theoretical in real science.

You just have to remember that your percent yield will always be less than 100 due to error, whether it be human error, machine error, or unknown error.

Finding percent yield can be pretty disappointing, too. It's like baking a batch of cookies and starting with all of this:

http://noentreecakes.com/wp-content/uploads/2015/03/Baking-Ingredients.jpg

Only to end up with this:

http://upload.wikimedia.org/wikipedia/commons/thumb/6/61/Single_chocolate_chip_cookie.jpg/300px-Single_chocolate_chip_cookie.jpg


Here are some websites that'll help you if you're struggling:

https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/mass-relationships-and-chemical-equations-3/reaction-stoichiometry-44/calculating-theoretical-and-percent-yield-234-4704/

http://www.sparknotes.com/chemistry/stoichiometry/realworldreactions/section2.rhtml

How to find the Excess

While studying for our unit test Monday, I found this source from another chemistry teacher online that made this chapter REALLY easy to understand! One of the most helpful things i took from his page was the simple algebraic equation that gave me the amount of excess product without having to set up another stoichiometry problem.

Here's the equation:

original amount of excess reagent - org. amnt of excess reagent(amount of product actually formed/amount of product excess reagent can make)

It helped me cut down the time it was taking me to find the excess product, and helped me make this chapter a little bit easier.

Here's the webpage if you wanted to check it out!

 http://misterguch.brinkster.net/chapter12.pdf

By the way, here is a random fun fact about stoichiometry from the page:

Stoichiometry

The Basics of Stoichiometry:

Step 1: Convert amount of substance A from grams to moles
Step 2: Multiply by coefficient/molarity ratio
Step 3: Convert substance B from moles to grams

https://www.chem.tamu.edu/class/majors/tutorialnotefiles/Stoichmap.gif


And that is all.....until you get to alterations.

Stoichiometry is all about taking that basic process of solving a problem and changing it and manipulating it to get the desired answer.

If you need any help understanding the basics of stoichiometry, check out these links:

https://youtu.be/SjQG3rKSZUQ

https://youtu.be/wUckvmyvMi8

http://www.chemteam.info/Stoichiometry/Stoichiometry.html

Acid-Base Reactions

The driving force of acid-base reactions is the production of water. These reactions also produce a salt composed of a cation from the base and an anion from the acid.

Strong Acids:
Produce H+
Protonate completely
are BrICl
O outnumber H by 2:1

Strong Bases:
Contain OH- anion
disassociate completely
all group 1& 2 metals

Weak acids and bases don't disassociate/protonate completely

Activity Series of Metals Lab

Today in class we did a lab involving different metals and solutions.

We took calcium, copper, magnesium, tin, zinc, and lead samples and placed them in different wells. Then, we added droplets of H2O, HCL, CuSO4, and AgNO3 to the metals in different trials to see how each substance reacted.

The purpose of this lab was to explore oxidation and reduction likelihood and to practice proving single replacement reactions.

Here is an image of the metals reacted with CuSO4 (top) and AgNO3 (bottom)

Redox Reactions

Redox reactions, also known as oxidation-reduction reactions are driven by the transfer of electrons. One of the tricky parts about these reactions is remembering the difference between oxidation and reduction. Contrary to what one would think, reduction is the process of gaining electrons, while oxidation is the process of losing electrons. One way to remember this is:

https://c3.100r.org/media/2013/12/bribery-probe-may-contribute-to-job-cuts-at-texas-oil-explorer/offshore-oil-rig.jpg

OIL RIG. This stands for Oxidation Is Loss of e- and Reduction Is Gain of e-

When solving these reactions , it is important to know how to find the oxidation # of reactants and products. Here are a couple of pictures that really helped me understand the concept.

http://image.slidesharecdn.com/redox-100512065957-phpapp01/95/redox-8-638.jpg

**ADDITIONAL INFORMATION**

Here are 2 great sites that will aid in further learning!

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwjpwKSkx7nJAhVSKogKHcPrBRgQtwIINTAF&url=https%3A%2F%2Fwww.khanacademy.org%2Fscience%2Fchemistry%2Foxidation-reduction%2Fredox-oxidation-reduction%2Fv%2Fpractice-determining-oxidation-states&usg=AFQjCNFNS_MtDJeF6BJvpdo5D3cFXTht1w&sig2=VQnpFOHiGF_VtGUho2X2fw

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0ahUKEwjpwKSkx7nJAhVSKogKHcPrBRgQFggvMAQ&url=http%3A%2F%2Fwww.occc.edu%2Fkmbailey%2Fchem1115tutorials%2Foxidation_numbers.htm&usg=AFQjCNFExV7dy5R5XyaeszAqZGYwDX5y9w&sig2=pxL7UEwLLUJYeIQQ1HR-gw

Balancing Chemical Equations

While seemingly simple, it is easy to make simple errors when balancing chemical equations.
Here's a picture explaining how:

When balancing equations with only Carbon, Hydrogen, and Oxygen, it is important to use the CHO method. That means that you need to balance the Carbon atoms first, then Hydrogen, and Oxygen atoms last.

**ADDITIONAL INFORMATION**
Here is a video explaining this concept if you need more practice: https://www.youtube.com/watch?v=eNsVaUCzvLA

Solubility Rules

Solubility rules are crucial to memorize in order to accurately understand and solve chemical reactions; specifically, precipitate reactions or double-replacement reactions. Here are these rules:

 Solubility Rules

1. Salts containing Group I elements are soluble (Li⁺, Na⁺, K⁺, Cs⁺, Rb⁺). Exceptions to this rule are rare.
    Salts containing the ammonium ion (NH₄⁺) are also soluble.

2. Salts containing nitrate ion (NO₃^-) are generally soluble.

3. Salts containing Cl ^-, Br ^-, I ^- are generally soluble. Important exceptions to this rule are halide salts of
    Ag⁺, Pb²⁺, and (Hg₂)²⁺. Thus, AgCl, PbBr₂, and Hg₂Cl₂ are all insoluble.

4. Most silver salts are insoluble. AgNO₃ and Ag(C₂H₃O₂) are common soluble salts of silver; virtually
    anything else is insoluble.

5. Most sulfate salts are soluble. Important exceptions to this rule include BaSO₄, PbSO₄, Ag₂SO₄ and
    SrSO₄ .

6. Most hydroxide salts are only slightly soluble. Hydroxide salts of Group I elements are soluble.
    Hydroxide salts of Group II elements (Ca, Sr, and Ba) are slightly soluble. Hydroxide salts of transition
    metals and Al³⁺ are insoluble. Thus, Fe(OH)₃, Al(OH)₃, Co(OH)₂ are not soluble.

7. Most sulfides of transition metals are highly insoluble. Thus, CdS, FeS, ZnS, Ag₂S are all insoluble.
    Arsenic, antimony, bismuth, and lead sulfides are also insoluble.

8. Carbonates are frequently insoluble. Group II carbonates (Ca, Sr, and Ba) are insoluble. Some other
     insoluble carbonates include FeCO₃ and PbCO₃.

9. Chromates are frequently insoluble. Examples: PbCrO₄, BaCrO₄

10. Phosphates are frequently insoluble. Examples: Ca₃(PO₄)₂, Ag₃PO₄

11. Fluorides are frequently insoluble. Examples: BaF₂, MgF₂ PbF₂.

Here is another source covering the same rules with examples:

Rule 1. All compounds of Group IA elements (the alkali metals) are soluble.

For example, NaNO₃, KCl, and LiOH are all soluble compounds. This means that an aqueous solution of KCl really contains the predominant species K⁺ and Cl^- and, because KCl is soluble, no KCl is present as a solid compound in aqueous solution:
KCl_(s) => K⁺_(aq.) + Cl^-_(aq.)

Rule 2. All ammonium salts (salts of NH₄⁺) are soluble.

For example, NH₄OH is a soluble compound. Molecules of NH₄OH completely dissociate to give ions of NH₄⁺ and OH^- in aqueous solution.

Rule 3. All nitrate (NO₃^-), chlorate (ClO₃^-), perchlorate (ClO₄^-), and acetate (CH₃COO^- or C₂H₃O₂^-, sometimes abbreviated as Oac^-) salts are soluble.

For example, KNO₃ would be classified as completely soluble by rules 1 and 3. Thus, KNO₃ could be expected to dissociate completely in aqueous solution into K⁺ and NO₃^- ions: KNO₃ => K⁺_(aq.) + NO^3-_(aq.)

Rule 4. All chloride (Cl^-), bromide (Br^-), and iodide (I^-) salts are soluble except for those of Ag⁺, Pb²⁺, and Hg₂²⁺.

For example, AgCl is a classic insoluble chloride salt:
AgCl_(s) <=> Ag⁺_(aq.) + Cl^-_(aq.) (K_sp = 1.8 x 10^-10).

Rule 5. All sulfate ( SO₄⁼) compounds are soluble except those of Ba²⁺, Sr²⁺, Ca²⁺, Pb²⁺, Hg₂²⁺, and Hg²⁺, Ca²⁺ and Ag⁺ sulfates are only moderately soluble.

For example, BaSO₄ is insoluble (only soluble to a very small extent):
BaSO_4(s) <=> Ba²⁺_(aq.) + SO₄^2-_(aq.) (K_sp = 1.1 x 10^-10).
Na₂SO₄ is completely soluble:
Na₂SO_4(s) => 2 Na⁺_(aq.) + SO₄^2-_(aq.).

Rule 6. All hydroxide (OH^-) compounds are insoluble except those of Group I-A (alkali metals) and Ba²⁺, Ca²⁺, and Sr²⁺.

For example, Mg(OH)₂ is insoluble (K_sp = 7.1 x 10^-12).
NaOH and Ba(OH)₂ are soluble, completely dissociating in aqueous solution:
NaOH_(s) => Na⁺_(aq.) + OH^-_(aq.), a strong base
Ba(OH)_2(s) => Ba²⁺_(aq.) + 2OH^-_(aq.) (K_sp = 3 x 10^-4)

Rule 7. All sulfide (S^2-) compounds are insoluble except those of Groups I-A and II-A (alkali metals and alkali earths).

For example, Na₂S_(s) <=> 2Na⁺_(aq.) + S^2-_(aq.)
MnS is insoluble (K_sp = 3 x 10^-11).

Rule 8. All sulfites (SO₃⁼), carbonates (CO₃⁼), chromates (CrO₄⁼), and phosphates (PO₄^3-) areinsoluble except for those of NH₄⁺ and Group I-A (alkali metals)(see rules 1 and 2).

For example, calcite, CaCO_3(s) <=> Ca²⁺_(aq.) + CO₃⁼_(aq.) (K_sp = 4.5 x 10^-9).

**ADDITIONAL SOURCES**

Website explaining the rules: http://www.chem.sc.edu/faculty/morgan/resources/solubility/

Here are some flashcards: https://quizlet.com/232395/solubility-rules-practice-flash-cards/

Here's a helpful song: https://www.youtube.com/watch?v=VJoKQ3ULCVs

Comments/Reflection

Part of the grade we receive for running this blog comes from completing 6 comments on other people's blogs. Here are my 6 comments!

P.S- In a mini reflection of the unit test, I thought it went terribly. I was completely confident in this unit and knew how to complete all problems accurately, but with the time given, I could only complete just about half of the questions. If I receive a low grade, it won't be because of my knowledge, it will be because of the time allocated. 

Hydrate Lab

Yesterday we did another lab in class. This time, it was about hydrates!

In this lab we determined the formula of the hydrate CuSO4 · nH2O.

We took 2 cm of the hydrate, weighed it, heated it to remove the water, and measured the mass of the dried salt.

With these numbers we were able to figure out the 'n' in the hydrate.



Here is a picture of us heating the hydrate to remove excess H2O,




*** If you're having trouble with the math equations for this unit, here are some helpful links that I studied from:
1. http://www.chemteam.info/Solutions/Molarity.html

2. http://www.chemteam.info/Mole/Avogadro-Number-CalcsII.html

3. http://www.chemteam.info/Mole/Empirical-MolecFormulas.html

Aspirin Lab

The other day we weighed our dried Aspirin after letting it sit out all fall break plus a few days. Once we obtained that measurement, we converted it into moles.


I used the data Lauren and I collected:

Starting mass of salicylic acid in grams: 5.0451 g
Mass of watch glass in grams: 36.8387 g
Ending mass of acetylsalicylic acid in grams: 5.1795 g
Mass of filter paper: 0.4114 g

Starting mass of salicylic acid (C7H6O3): .03652 mol C7H6O3

Ending mass of acetylsalicylic acid (C9H8O4): .02875 mol C9H8O4

Chemical Composition Equations

These equations intimidated me when I first saw them. But, once I broke them down and wrote why numbers were what they were, they seem OK. Here's how I keep things organized:

1. Find mass of hydrate (everything in the test tube/crucible)
2. Find mass of anhydrous salt (I write down 'salt' to simplify things)
3. Find mass of H2O (hydrate -  salt)
4. Convert amount of H2O and amount of salt into moles
5. Divide water from salt ( H2O/Salt)
6. Round to whole number.

Hope this helps! If you're still confused, here are some good ~*LINKS*~ to check out:

1. Hydrate Help from Chem.com

2 Help from Study. com (pictures)

3. Here's a video if you're a visual learner: http://study.com/academy/lesson/hydrates-determining-the-chemical-formula-from-empirical-data.html

Pretest

Last pretest I got a 55%. This time, I got a 33%. If that doesn't say anything, then I don't know what will. I am going into this unit with absolutely no prior knowledge, so I will definitely have to buckle down and study hard. I know that moles are sorta cute little fuzzy creatures, but once they're thrown into chemistry- I no longer like them. We will see how this unit turns out; with the topic being so foreign and the grading scale being much different.

This...

https://universityofnebras599-public.sharepoint.com/SiteAssets/species-information/moles/Fig%202%20Ventral%20view%20of%20eastern%20mole.jpg


Goes to this....


https://www.chem.tamu.edu/class/majors/tutorialnotefiles/stoich9.gif

Significant Figures

Out of all the things covered in this unit, significant figures was my least favorite. For some reason, this concept just did not agree with me. One of the things that really helped me understand it though was this simple picture:


http://cbchemistry.weebly.com/uploads/1/0/7/1/10716575/1034036_orig.jpg

Having the rules laid out in front of me cut and dry made things very easy to understand. It paid off looking at this chart, too, because I ended up doing really well on my test! Thanks google. :)

Here is a website that really helped me out!

If you're still stuck, here's another site that explains it a different way: in tutorial form

Mole Day!

Last Friday, we had mole day. What is mole day, you ask? Well quite simply, we celebrated the unit of a mole! A mole is 6.022 x 10^23. This was determined by the number of particles found in 12.000 grams of carbon-12; a mole of carbon-12 atoms has 6.022 x 1023 carbon-12 atoms. A mole is also known as Avogadro's Number. To celebrate the mole, we all made stuffed moles and brought in food!

Here are all of our moles: 

 If we zoom in a bit here I think we can spot my mole...

It beautiful. 

Happy Belated Mole Day.

***Helpful Hint: this website is great to learn more about a mole.

Aspirin Lab Day 2

On day 2, we continued the lab by isolating the product.

First we set up the Buchner funnel and wet the filter paper to ensure good suction.

We then poured the aspirin solution into the funnel. The flask was rinsed with water and poured into the funnel to make sure no crystals were left behind. Then we dried the crystals by pulling air through the funnel for 15 minutes.

Once the excess water was removed, we removed the filter paper with the aspirin on it with tweezers and place it on a watch glass. We moved the aspirin onto a double folded paper towel and placed this on a side table to completely dry over fall break.

If you wanted to know more about how a Buchner funnel is used, check out this awesome video for more information.

Also, more information about the chemical changes occurring during the synthesis of aspirin can be found on this informative website.

Aspirin Lab Day 1

Because my partner Lauren and I passed the prelab questions, we got to do the Aspirin Lab.

On the first day, we first weighed out 5.00 g of salicylic acid, added 7.00 mL of acetic anhydride, and 8 drops of sulfuric acid to an Erlenmeyer flask.

Then, we assembled a hot water bath in an 800 mL beaker and placed the flask with the chemicals into the bath. Once it started boiling, we let it boil for 15 minutes.

Once it finished heating, the flask was removed and left to cool for 3 minutes on the lab bench. Then 15 mL of ice cold water was added to remove the excess acetic anhydride.

We mixed the content and left it to crystalize for the next day.

If you wanted to know the actual process of how aspirin crystalizes, check out this awesome website to learn more!

Post- Unit Exam

I found this unit to be really easy for me personally. Last unit, I had a really tough time learning all of the polyatomic ions and remembering the different ways to name compounds. Once I got that unit down, though, this one was a breeze! The pretest seemed impossible, but once the information was given to us, it all made sense (funny how that works). I was actually pretty excited for this unit because I used to want to be a nuclear engineer. Also, decay and half life was interesting to learn about because it can tell us so much that I would have never thought we could know! I think I did okay on the test, but whenever I say that I end up doing bad, so fingers crossed. Overall, I enjoyed this unit and am curious to hear what we will learn about next.

Alpha Beta and Gamma Radiations

The three different radiations can be a little bit confusing to keep separated in my mind, so I thought compiling my information and creating a blog post might solidify some information. :) 

Alpha Radiation/Decay
The symbol for alpha radiation is 

Symbolized with a sideways fish that I can't type.

Helium nucleus

Mass # -4
Atomic # -2

Beta Radiation/Decay

The symbol for beta radiation is 

Symbolized with a fancy capital B that I also cannot type.

Electron

Mass #- no change
Atomic #- +1

Gamma Radiation/Decay

The symbol for gammas radiation is 

Symbolized with a lowercase fancy Y that I, yet again, cannot type.

Releases high energy forms of light called photons.

Mass #- no change
Atomic #- no change

Accompanies alpha and beta decay. 

I found this website extremely helpful in learning more about the three different type of decay.
Also, this video is helpful  to learn how to write nuclear equations with these 3 radiations.

Mid- Star Project

     As of right now, we are in the middle of completing a "star project". This is where we look up stars, find their location, chemical composition, stellar classification, and the spectral analysis of the most abundant chemical. The first five or so stars were super hard to complete just because of the research aspect- it took me 30 minutes (on average) per star! The odd objects in space took even longer. I decided to do a black hole, a supernova, and a crab nebula. The number of research papers I read alone was astounding! 

     Then, when I only had 2 or 3 stars left, Mrs. Frankenburg posted these awesome resources on schoology. This website here allows you to search for stars based on location or even just name. It then gives you all the information required to complete this project-- how handy! Then, Mrs. Frankenburg posted a link to this collection of visible spectra of the elements.  This allowed me to paste the spectral analysis of all the needed elements (even though most of the time it was Hydrogen). This project is coming along nicely and it is interesting to learn about objects so far away. I will post on my blog once the entire project is complete. 

Beanium Lab

Yesterday in class we did a lab about a newly discovered element, Beanium.

We had a sample of different isotopes of the element Beanium and had to record their frequency and mass. One of the things we did first was measure the cup without any beanium in it to ensure accurate measurement.

 Then we did the rest of the experiment, measuring each different isotope to find the average atomic mass.

This lab helped me learn how to use the equation to find average atomic mass and the importance of taking every isotope into account. 

**Helpful hint: I found that this website is really helpul if you're having trouble figuring out how to calculate the average atomic mass! 

Atomic Theories

Here are all of the atomic theories we learned about in class:

Dalton's Atomic Theory

• all elements are composed of atoms
• all atoms of an element are identical WRONG. isotopes
• atoms of different elements are different
• compounds are formed by a combination of two or more different kinds of atoms
• atoms are indivisible, nor can they be created or destroyed. Atom bomb disproves this. 

JJ Thompson

• used cathode ray tube to show atoms of any element
• chocolate chip cookie model
• electrons placed randomly in positive matrix
• distinct border

Rutherford's Gold Foil Experiment

• proved presence of + charge in the center of an atom
• area of + charge small and dense 

Current Atomic Model

• cloud model 
• electrons located pinpointed with probability
• Schrodinger wave 

Pre-Unit/ Reflection of Pretest

Why am I interested in this unit?

I used to want to be a nuclear engineer, so learning about decay and atomic structure has always fascinated me.

What am I excited to learn?

I'm excited to learn about what goes on inside a nuclear reactor.

What do I not know?

I have not learned about the density of a nucleus, the difference between gamma, beta, and alpha radiation, how to balance nuclear equations, and the laws regarding nuclear science.

What do I think I'll have the most trouble with this unit?

I think remembering the difference between the three different radiations will be hard.

How did the pretest go?

I was confident in literally 1 answer. There is a lot to learn.

Naming Acids

Naming acids depends on whether you can identify polyatomic ions and recognize an acid. All acids have an H in the cation position (first). 

Reference Tables for Chemistry (2011) Retrieved from: https://castlelearning.com/review/reference/chem%20table%20e.htm


**Helpful hint: I found that this website is VERY helpful if you're having trouble naming acids!! 

Naming Type 1 2 and 3 Binary Compounds

Type 1 Binary Compound:


Type 2 Binary Compound:
metal + non-metal
roman numerals to indicate charge on metal


Type 3 Binary Compounds:
1 elements named as is, second element named as anion (add -ide at the end).
Composed of 2 non metals.
Use prefixes to establish element frequency.
1- mono
2- di
3- tri
4- tetra
5- penta
6- hexa
7- hepta
8- octa
9- nona
10- deca

(9 March 2011) Retrieved from: http://www.slideshare.net/mn_mikaelian/chapter-5-compounds

Introduction

My name is Marie Dishian and I am currently a junior at Francis Howell High School. I am an aspiring medical researcher and this blog is part of my Pre-AP Chemistry class. I've played Varsity soccer since freshman year at the school and currently am playing on my club team. As for clubs, I am part of NHS, HOSA, Student Council, Viking Edge (Link Leadership), and the Torch and Laurel society. My favorite food is watermelon.