Thursday, March 28, 2013

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!

Friday, March 22, 2013

Blog Week 24

On Monday talked about an experiment, we did a stimulation on the internet of rubbing a balloon on a sweater and seeing if it attracts to the wall and sweater. When the balloon was rubbed against the sweater, the balloon took the negative charges through static friction. The balloon got a negative charge and the sweater is now a positive charge and the wall has a neutral charge. The balloon was attracted to the sweater because they had opposite charges. The balloon was also attracted to the wall, but it was a very small attraction, because the wall had a neutral charge. This picture below shows the balloon attraction to the sweater and the wall.
We then learned some terms. Neutral has equal (+) and (-), evenly distributed charge. Charged is unequal (+) and (-) charge. Polar is equal (+) and (-), but uneven distribution. Dipole are organized charges at different ends, they are exact opposites. We also learned that the only charges that move are negative charges. Tomorrow we are learning about how charges have to do with compounds. On Tuesday, we talked about dipoles. We found out that H2O are dipole atoms. Which means that oxygen has a slightly negative charge and hydrogen has a slightly positive charge. So when two H2O atoms are by each other the oxygen attracts to the hydrogen molecules. The structure that it makes is called a crystal lattice structure. Water melting means enough energy to separate the attraction of each molecule between each other. IMFs are intermolecular forces, electrostatic attraction between molecules because of dipoles. IMF is also a dipole interaction involving H atoms in molecules. We then learned that ions are atoms with a charge and an atom that has an unequal amount of (+) and (-) charge and lastly it loses or gains an electron. If Na atom loses an electron then it turns in an ion and becomes a Na+1. If Cl atom gained an electron then it turns into an ion and becomes a Cl-1. We found out that electron carriers are oxygen and NAD+, they transfer electrons to other molecules. To make ionic compounds it would be like this: Na+1<-->Cl-1 = NaCl. On Wednesday, we did a worksheet. I understood question 1-4, but the rest were very difficult. I tweeted out my answers and these pictures show my answers to the questions.

On Thursday, we were to do the worksheets skill practice 19 and chem Quest 19. I worked alone on both worksheets. I understood the answers once I worked backwards on how to find the answer. I hope I have the right idea. I was going to redo the worksheets to practice for the assessment tomorrow. I hope I can understand it enough to do well on the assessment. Also, I tweeted my answers to both worksheets. On Friday, we took an assessment. I felt like I did pretty good, I understood almost all of it. I hope I did good.


Friday, March 15, 2013

Blog Week 23

On Monday, I was absent. On Tuesday, I was absent. On Wednesday, we talked about the lab that was done on Tuesday. I didn't really follow the talk about the lab. I learned that an electron is smaller than an atom and it has a negative charge. Atoms where discovered by John Dalton, while electrons where discovered by JJ Thomson, he did the experiment that proved electrons had a negative charge. In the atom there's a positive charge all around the electrons. It's like plum pudding the electrons are the plums and the positive charge is the pudding. When two neutrals are rubbed together, after that they each get a separate charge, one positive and the other negative. Negative and positive attract, negative and neutral attract, positive and neutral attract. On Tuesday, we did an experiment to find out which materials could conduct electricity. We found out that metals are conductive. This is a list of materials that are conductive: silver fork, silver plate, foil, copper, iron, brass, pop can and license plate. This is a list of materials that are not conductive: card board, glass and water. We also learned that electricity is the flow of electrons. On Friday, we talked about particle diagrams. We talked of how electrons move through each material, but they have to be conductive. I'm still not sure I get all of this information, but I will caught on eventually.

Saturday, March 2, 2013

Blog Week 21

On Monday, we continued practicing with mol problems. My group got question seven from unit five worksheet two. We got the atomic mass for iron, which was 55.8g, but since the substance was Fe2O3 we timed 55.8 x 2 = 111.6g. Then we got the atomic mass for oxygen, which was 16g, then we timed 16 x 3 = 48g because the substance was Fe2O3. After that we added those two numbers together to get 159.6 and that number is the mass for one mol. So, we then set up the equation: 2.50kg x 1000g/1kg x 1mol/159.6g, we added the 1000g/1kg because the masses need to be the same unit, so they could be canceled out. The answer we ended with was 15.7 mol Fe2O3. We then listened to the other groups questions, which were numbers six and eight. They each got the right answers, I did the same problems for extra practice, in the picture below is my work on the problems.


On Tuesday, went over how to do the problems we've been practicing in class. We first talked about turning grams to mols. First you find the molar mass of the substance in question, it relates the grams for every one mol of the substance. We then add up the molar masses of all the atoms in substance. We then came to the conclusion that the equation is: 1mol/mass(g) x g = mol. We then talked about how to turn mol into grams. First you have to find the molar mass and add up all the atoms. We the decided that the equation is: mol x mass(g)/1mol = g. Then we went onto say the equation for mol to molecules is: mol x 6.02x10^23molecules/1mol = molecules. So to get molecules to mol the equation is: molecules x 1mol/6.02x10^23molecules = mol. At the end of class we were introduced to the electrolysis apparatus.
On Wednesday, we had a shortened period, sadly to say goodbye to Mr. Toby. During the class we did an experiment, creating hydrogen and oxygen gases by adding electricity to the system. The information we wanted to obtain was the volumes of each gas, along with mass, molar masses, and mols. I got the measurements and wrote them down, but I wasn't if they were correct. On Thursday, I fixed and my work and my group ended up being correct. The volume of hydrogen was 2 and the volume for oxygen was 1. From their used the densities I looked up on Wednesday, but we had to convert them, because they were in liters not milliliters. We then wanted to find the mass. So for hydrogen this was our equation: m/2 = 89.88, m = 0.1798g. Then equation for oxygen's mass was: m/1 = 1.429g. Then we needed to find the mols. So we had the molar masses, which are the atomic masses and since it was H2 and O2, we multiplied the molar masses by two. So, hydrogen's molar mass was 2.02 and oxygen's molar mass was 32g. To get mols we set up the equations for oxygen and hydrogen. Oxygen's equation was: 1/32 x 1,429 = .0447 mol. Hydrogen's equation was: 1/2.02 x 89.99 = .089mol. Which proved that water was H2O a 2 to 1 ratio. You called it the empirical formula. You said based on the mass we can find mol, then find the ratio and then the formula. (I hope I all the numbers are right, you told us we needed to divide by a 1000 instead of multiply by 1000, so I hope I fixed it right.) This picture below shows my groups data. The one on the right is the set up of the experiment.

On Friday, we took an assessment. I didn't really like taking it on my phone. I guess I'm old fashioned in my test taking. I prefer to do my tests on paper. I think I did ok on the assessment, but some questions were really confusing.

Friday, February 15, 2013

Blog Week 20

On Monday, we went reviewed what we were talking about on Thursday. We learned that when comparing one element's mass to another, we get a ratio that is unique to those elements. We did some examples and my group got assigned question six, but we didn't finish it completely. We did an equation that is: x=mg, 0.65x=O, x+0.65x=100g and we got the answer earlier and x=60.6g. This picture below shows another example we did. The first part is each element over the whole solution. The second part we divided the top number by the bottom to get a decimal then moved the decimal place over to get a percentage. These percentages where the percentage of each element in the solution.


On Tuesday, we did a lab. We wanted to find how much and how many of each hardware tool we had. We related how much to how many, which for food is serving size, but for our experiment we called it Quinn. We also wanted to find the relative mass of each hardware, which is the mass divided by the smallest mass. The picture below shows the results from the lab. For the Quinns we did the mass of the whole jar mass minus the empty jar to get a Quinn.




On Wednesday, I was absent.
On Thursday, we learned about a mole and molar mass. A mole is a group of particles that contains Avogadro's number of particles. Another definition is that it is the measurement that relates how much to how many. The last definition we gave it was a proportion of grams to the number of particles. One mol of Hydrogen. We learned that the molar masses are compared to Hydrogen. Molar mass is the same as the relative atomic mass relative to Hydrogen. This picture to the left shows some molar masses of some substances. Atomic mass unit, a.m.v., equals one Hydrogen unit to measure atoms. Relative atomic mass and molar mass are the same number, but different units. So we did a problem, it was this: 55.845 amv x 6.02 x 10^23 = 55.845 g. You can see in this problem the numbers are the same, but the units changed.
On Friday, we had a sub, so we did a worksheet. I did numbers one through three and my group got assigned number four. I did all the questions right I checked them using the answer key on google drive. I understand how to do these problems now. I know that you must know the atomic masses of the elements to solve the problems. I tweeted you number four on Friday during class.  I did one through three in my notebook.

Friday, February 8, 2013

Blog Week 19

On Monday, we did Zn + HCl Lab. But first we discussed the properties of gaseous substances, which were combustibility and flammability, which mean the same thing. For the lab we took the trough filled it with water, put a bell jar full of water over the hole and then had a flask of hydrochloric acid and we dropped zinc into it. Once the system was topped off with the cork, the bell jar captured the water. We wanted to find the mass, volume and density of the system before and after the we added the zinc. In my group though our stopper/cork was too small to close the system, so we did not get any measurements. On Tuesday, my group got a chance to redo the experiment and actually see the gas get collected and test if it was combustible. We found out that the gas made was combustible. Our observations from the experiment were that the hydrochloric acid looked like water, the flask got warm when we added zinc and after combustion the flask got colder. We then considered what the gas in the bell jar could be. We decided we had three options: hydrogen, chlorine, or zinc. We eliminated chlorine because it's a yellow color and a poison and we also eliminated zinc because it has a high boiling point. So, the gas made had to be hydrogen, because it was the last option left and H2 is combustible. But, as we tried to figure out our equation we noticed that a second compound was made ZnCl2. We also noticed that a third was mad that was H2O because the hydrogen combined with the oxygen in the air to create water. We know this because there was condensation inside the bell jar after combustion. The picture below shows the equation for this lab.

On Wednesday, I worked on the skills practice worksheet. I understood how to balance the equations, but other than that I wasn't sure how to complete the other things.
On Thursday, we talked about diatomic elements, they in pure element form and they come in pairs. We learned that when they join into other compounds the diatomic element become single atoms. We then talked about how H2O and H2O2 compared, we assumed that all their atoms were the same mass/size. So, we did an experiment to test our theory. We took Magnesium and set it on fire. But we measured the mass before and got .37g. After we combusted it we knew that it'd combine with the oxygen in the air to make 2mgO. So the mass after we combusted it was .45g. This proved that we can't assume atoms are the same size. Oxygen mass= 21% mass of mg.
On Friday, we had a snow day!!

Sunday, February 3, 2013

Blog Week 18

On Monday, we didn't have school. On Tuesday, we went to computer lab. In the computer lab we did a virtual lab and answered questions. On Wednesday, we went over the virtual lab. We the learned that are diatomic gases and some of those are oxygen, chlorine gas and phlogiston.

In this picture we can see that there are two phs in each of the first two boxes and the last two. Then there are two Os in the third box and the last two boxes. We learned that if the we combined an O to each of the ph boxes we'd get a mystery gas.

In the next drawing we see that the mystery gas is water, which lead us to the conclusion that phlogiston is hydrogen. Which the picture to the right shows that it is in fact hydrogen. The equation is H2+O= 2H2O.

The picture to the right shows the equation for hydrogen chloride. It's H2+Cl2= 2HCl. This is the equation because you must spilt up have an equal amount in each box at the end, and to get that one H and one Cl had to be in each box which gave the gas HCl.





This picture to the right shows that if you were to have the equation 4H2 + 4Cl2 it would equal 8 HCl. It's that because, the equation H2+Cl2 it would equal 2HCl. So, we'd could multiply 2HCl by 4 and get 8HCl.






This picture to the right shows an equation with elements. We want to divide them up evenly. We can spilt compounds and make compounds to get the answer. We stopped here on Wednesday.

On Thursday, I left school early, not feeling well, so I missed the explanation.

On Friday, I had a doctor's appointment, I'm pretty sure I missed an assessment.