Blog Week 32

On Monday, we talked a little more about the Nail lab. We wanted to know the reasoning for the rise in temperature of the test tube. We learned that breaking bonds requires energy and when energy increases, so does the temperature. The energy to break the bonds comes from the chemical energy. An exothermic reaction is when energy of the reactants were greater than the products, therefore extra leftover energy exited the system. An Endothermic reaction is when extra energy would need to enter the system before the reaction could take place. On Tuesday, we tried to do some worksheets in class, my group got number three. The picture below is our work:
On Wednesday, we had a sub and we were to do a worksheet. I didn't understand how to do any of it really. I did attempt a couple  for one I got PE + KE = U. Then I attempted number five and got a) increase b) increase c) increase d) decrease e) decrease. I need help understanding the LOL diagrams. On Thursday, we had a tutorial, because Mr. Abud won teacher of the year. Congratulations Mr. Abud! On Friday, we reviewed everything we've learned this year to prepare for the final.

Blog Week 31

On Monday, we started out lab. Our lab was seeing what happens when an iron nail is put in a mixture of Copper Chloride and distilled water. We first massed our nail which came out to be 15.8g. Then we massed our distilled water to be 50mL. after that we weighed the plastic container that would hold the Copper Chloride and that came out to be 3.1g; then we added the Copper Chloride and the mass for the Copper Chloride minus the container came to 6.5g. When we poured the solution into a test tube and the test tube was too small, so we had 24mL of the solution was left over. So, our measurements will probably be off. We did observe what happened to the nail once it was in the solution. We noticed that the nail started turning red and the test tube became warm. This is the reaction equation I have so far for this experiment: Fe + CuCl2 = FeCl2 + Cu. On Tuesday, I was absent. On Wednesday, I picked up with the lab. We measured the nail after it soaked in the solution and it weighed 14.5g. Then we weighed the copper by weighing an empty beaker then subtracting that from the beaker holding the copper. The amount of copper was 2.5g.  We also found the amount of iron by subtracting the first nail mass minus the last nail mass and it came to 1.3g. After that we did out calculations to turn the grams into mols. The equation is mass x 1mol/molar mass= mols. So, for Cu we did this: 2.5g x 1mol/63.5g = .0393 mols of Cu. Then we did Fe: 1.3g x 1mol/55.85g = .0232 mols of Fe. We then found the ratio .0393/.0232 = 1.69. Which is close to a 3 to 2 ratio. From here we went wanted to find out if our balanced equation was right. We learned that Fe could have a charge of +2 or +3. And since the ratio is very close to 3 to 2, we decided that in this situatuion Fe had the charge of +3. So, our balanced equation was 3CuCl2 + 2Fe --> 2FeCl3 + 3Cu. On Thursday, we talked about how next week we are doing the silver coke lab! Where we will turn silver+ to a simple silver. We then went on to discuss more about our nail lab. We came to the conclusion the iron had a charge of +3. We then learned that there were mini reactions with in the bigger reaction. They are called coupled reactants and they were these: Cu+2(aq) + 2e- --> Cu(s) and Fe(s) --> Fe3+(aq) + 3e-. (aq) stand for dissolved in water. The first one gains an electron and it's called a reduction. The second one loses an electron and it's called an oxidation. In this reaction is a redox, it's a coupling of a reduction and oxidation together. On Friday, we had an assessment, I'm definitely going to reassess.

Blog Week 30

On Monday, each group brought their cookies made with a different recipe. My recipe ended up being the real recipe. Other groups had too much of one ingredient or too little of an ingredient. This project was done, so we could understand what limited reactants and an excess reactant was. A limited reactant is a substance that is completely used up in a chemical reaction. An excess reactant is a substance that is partly used, after the chemical reaction there is still some of the reactant left over. On Tuesday, practiced with some problems on stoichiometry. First we balanced the equation, then we decided which reactant was limited and which one was excess. From there we figured out the ratio and continued with the problem doing the same steps from last week's lessons. Here's an example below:

               CH4 + 2O2 --> 2H2O + CO2  <-- need to balance equation

Before:   2.5xs   2.5LR        Ø           Ø     <--- Ø because it's being produced 

Change:  -1.25    -2.5        +2.5      +1.25 <-- are mols  

________________________________  <-- -1.25 bc it was a XS, and it was a 1:2 ratio, only 1/2 of 2.5 

After:        1.25      0          +2.4     +1.25

We also drew particle diagrams. I shows this chemical reaction in the picture below.

On Wednesday, we had a sub and we did more practice on limited and excess reactants. We also worked on converting moles into grams and grams into moles. 

Here are some examples:

3.

               2Al    +  3I2 --> 2AlI3  <-- need to balance equation

Before:   .50 xs  .72 LR      Ø       <--- Ø because it's being produced 

Change:  -.48    -.72        +.48      <-- are mols  

___________________________<-- -.48 bc it was a XS, and it was a 2:3 ratio, only 2/3 of .72

After:       .02       0          +.48     

4. Na2SO4 --> g    .20 mol--> g  Na2SO4 = .20 mols and molar mass = 142 

 .20 mol x 142g/1 mol = 28.4g 

On Thursday, we learned about yield percent. the equation for it is actual/theoretical. An example is 35g NaCl/50g NaCl = .7 = 70% 

We also worked on more examples like on Wednesday. Here is another example:

               2KCIO3  --> 2KCI + 3O2  <-- need to balance equation

Before:       1.2                0          Ø      <--- Ø because it's being produced 

Change:    -1.2           +1.8       +1.8    <-- are mols  

_____________________________  <-- -1.2 bc it's a 3:2 ratio, 3/2 of 1.8

After:          0              +1.8      +1.8

On Friday, I was absent. We were to take an assessment. 

Blog Week 29

On Monday, I was absent. On Tuesday, we worked on reactant equations. We watched Ethanol react with something and oxygen. Then we tested to see if it would combust and it did. A combustion reaction makes carbon dioxide and water.

Combustion -> CO2 + H2O. We had an equation for our experiment it was: C2H6O + 3O2, we found the molar mass for C2H6O = 46.08 g/mol and the molar mass for 96 g/mol. So, 46.08 + 96 = 142.08 g/mol. Then we found the reaction equation C2H6O + 3O2 -> 2CO2 + 3H2O. The molar mass for 2CO2 is 88.02 g/mol and the molar mass for 3H20 is 54.06 g/mol. So, 88.02 + 54.06 = 142.08 g/mol. So, the reaction equation is right because the molar masses are equal from before and after the reaction. C2H6O + 3O2 -> 2CO2 + 3H2O, so for every 1 C2H6O there's three H20. Then for every 50 C2H6O there's 15o H2O. We also, went over the equation for g<--> mol, they are g x 1mol/__g = __mol and mol x __g/1mol =__g. On Wednesday, we learned how to do BCA tables. We did a practice:
               2H2S + 3O2 --> SO2 + 2H2O <-- need 3O2 to get rid of 2H2S.
Before:   +2.4       XS          Ø           Ø     <--- Ø because it's being produced 
Change:  -2.4       -3.6        +2.4      +2.4  <-- are mols  
________________________________  <-- 3.6 because it's a 2:3 ratio, (3/2) x 2.4 = 3.6 
After:        0           XS        +2.4      +2.4

After that we wanted to find out how much (g) of H20 did we produce?
mol x molar mass/1 mol = g
2.4mol H2O x 18g/1 mol = 43.2 g.
    ^                      ^
in equation      H2=2 and O = 16 H2O = 18

On Thursday, we did more examples:

2.            C3H8 + 5O2 --> 3CO2 + 4H2O <-- needed to balance equation

Before:       +4       XS          Ø           Ø       <--- Ø because it's being produced 

Change:      -4       -20        +12        +16     <-- are mols  

________________________________    <-- 4 bc it's a 1:3 ratio, (1/3) x 12 = 4; 20 bc 1:5, (1/5) x 4 = 20

After:           0         XS        +12      +16          16 bc 1:4, (1/4) x 4 = 16

6.           3H2 + N2 --> 2NH3 <-- need 3H2 to get rid of N2.

Before:   .45     .15           Ø     <--- Ø because it's being produced 

Change:  -.45    -.15       +.30  <-- are mols  

________________________<-- .45 bc it's a 3:1, (3/1) x .15 = .45 and .30 bc it's a 2:1, (2/1) x .15 = .30   

After:       0         0          +.30

Then we wanted to find how much (g) of 2NH3 we produced?

molar masses N=14 H3=3 

17g/1mol x .30 = 5.1 g of 3NH3.

On Friday, we took an assessment. I think I did okay, but I didn't know the type of chemical reaction. Then I took the assessment from last week. I understood everything, except the chemical reactions.

Blog Week 27

On Monday, we were in the computer lab working on a way to help us name compounds. On Tuesday, we continued our work on that, I used popplet to do my work. This is the link to my work: http://popplet.com/app/#/941419. We also talked about blogs and how they will now be graded. Nathon Jones will be grading my blog and I will be grading his. He will make sure I fully understand what we learned during class and if I added pictures. On Wednesday, we did an experiment. We took 70mL of HCl acid and mixed it with .5 grams of metal. But first we filled the trough with water and two bottles full of water to catch the gas and we could find out the amount of gas by water displacement. We then added the calcium metal to the HCl acid and gas began to fill up the bottle. At the end of the experiment we collected 650mL of gas, which converted into 0.65L of gas. While the gas was being made the flask became warm and the HCl acid became white and cloudy. Once we collected the gas we tested it for combustibility and it was combustible. We found out that 0.10 mol is in 1L. There was 0.07L of HCl and I can not figure how to convert it to mols, I know 1L is 0.10 mols but I don't know how to get 0.07L into mols. Then Calcium had a mass of .5 and I used the equation grams to mols to get the number of mols for Calcium. 0.5/x = 40.08/1 -> .5=40.08x -> x = 0.0125 mol. The number of mols is 0.0125 for Calcium. I haven't figured out the gas that was produced yet. Here are some pictures from the lab:

 On Thursday, we debriefed our lab. We wanted to answer these questions: 1) Temperature change? 2) The gas? 3) Chemical reaction? 4) Stoichiometry?. Stoichiometry means the measurement of chemical reactions. The temperature changed in the flask, when the calcium was added to the Hydrochloric acid, the flask became warm. The gas that was created was CaCl2 + H2. The equation was Ca + 2HCl -> CaCl2 + H2, because Ca and H can't combine because they are both positive, but for Ca and Cl to combine we need one Ca with a charge of +2 and two Cl to get a charge of -2; to "cancel" out the the Ca charge. Then the H2 is there because it doesn't dissolve. The ratio for this problem: 1 Ca need 2 HCl. Reaction is the arrangement of atoms to form different substances. On Friday, we worked on the three worksheets we got on Thursday. I finished all the worksheets and tweeted my whiteboard picture to Mr. Abud. Here's some questions from the worksheets:
~BaCl2 + F2 -> BaF2 + Cl2. This is the reaction because Ba has a charge of 2+ and Cl has a charge of 2- and F2 has a charge of 2-. So Ba combines with F2 because they make a neutral charge together and Cl2 doesn't go away and it can't combine with the neutral charge.
~NaCl + Ag -> AgCl + Na This is the reaction because Na has a charge of 2+ and Cl has a charge of 2- and Ag has a charge of 2+. So, Ag and Cl combine to become a neutral compound and Na doesn't go away.

Blog Week 26

On Monday, we all shared what we did over break. Then we reviewed some things. We talked about the experiment, where we undid the compounds. We undid the compound CuCl to get separate atoms copper and chloride. We undid the compound by moving electrons around through the system. On Tuesday, we talked about vocabulary. Molecules have can have a positive or negative or neutral charge. Atoms have a neutral charge and when they gain or lose electrons, they become ions and ions have a negative or positive charge. Compounds have a neutral charge. There are two types of compounds we are working with, ionic compounds and molecular compounds. Ionic compounds are compounds of ions that form neutral charges and metals and nonmetals are bonded to together to form the compound. Molecular compounds are nonmetals and nonmetals bonded together. Polyatomicion are  compounds with charges. Below and to the left are some examples:

We also went over how to figure out charges of each atom in a compound. Below and to the right is an example:


We went over how to bond an polyatimicion compound with atoms to make them neutral. From example SO4charge-2 is combined with 2 Na because Na has a charge of +1 and if we use two Na with SO4 they will cancel out each other's charges forming a compound of Na2SO4. On Wednesday, I was absent. On Thursday, we did some visual learning with people being electrons and atoms. I tried my best to take notes on the example and they are to the left. We then did then the worksheet and I understood it pretty good and it will come in handy to study from.
On Friday, we took an assessment and I understood most of the questions. I hope I did good on the assessment.

Blog Week 25

On Monday, we turned in our electroscopes. We tested them by rubbing a balloon to our shirts, then I put the charged balloon to the copper coil on the top of the jar. I know it worked because once I put the balloon to the copper coil the aluminum foil leaves that were in my jar, connected by the copper coil, moved apart. The way this all worked was: when I rubbed the balloon to my sweater it collected electrons, then when it was put to the copper coil the copper took the electrons from the balloons, then those electrons charged both aluminum foil leaves with negative charges, which caused them to repel against each other. Once the aluminum foil leaves and electroscope were charged, I put a zinc plate to the copper coil at the top of the jar and doing that took away the electrons in the aluminum foil leaves, and once the electrons were transferred to the zinc plate, the aluminum foil leaves didn't have a charge so they didn't repel. Here are some pictures below:

  

On Tuesday and Wednesday, I was absent. On Thursday, we mixed calcium acetate, which an ionic compound and ethanol, to make sterno. Once we mixed the two things together and they combined making a solid, we light the solid on fire and it made a fire. Then we roasted marshmallows. Here are some pictures of our fire:

  

On Friday, we don't have school. Hope you have a great spring break!