Wednesday, May 18, 2011

Exam Review #13

a.       1.2 g NaCl x (1 mol NaCl/58.44 g NaCl) = .021 mol NaCl
.021/.450 = .047 M NaCl
b.      .40(.650) =.26 mol
c.       M1V1=M2V2
          .100(.200)= 12.0(V2)
          .00167 L
          1.67 mL of stock solution
           198.33 mL of water will be needed

Thursday, April 7, 2011


Incident at Chernobyl

How the Nuclear Reactor Works-
·         First, uranium fuel is loaded up into the reactor—a giant concrete dome that's reinforced in case it explodes. In the heart of the reactor (the core), atoms split apart and release heat energy, producing neutrons and splitting other atoms in a chain reaction.
·         Control rods made of materials such as cadmium and boron can be raised or lowered into the reactor to soak up neutrons and slow down or speed up the chain reaction.
·         Water is pumped through the reactor to collect the heat energy that the chain reaction produces. It constantly flows around a closed loop linking the reactor with a heat exchanger.
·         Inside the heat exchanger, the water from the reactor gives up its energy to cooler water flowing in another closed loop, turning it into steam. Using two unconnected loops of water and the heat exchanger helps to keep water contaminated with radioactivity safely contained in one place and well away from most of the equipment in the plant.
·         The steam from the heat exchanger is piped to a turbine. As the steam blows past the turbine's vanes, they spin around at high speed.
·         The spinning turbine is connected to an electricity generator and makes that spin too.
·         The generator produces electricity that flows out to the power grid—and to our homes, shops, offices, and factories.
What Went Wrong at Chernobyl
The Chernobyl accident in 1986 was the result of a corrupted reactor design that was not operated by fully trained personnel. It resulted in a steam explosion and fires released at least 5% of the radioactive reactor core into the atmosphere. It started when engineers at Chernobyl conducted an experiment to find out if low power from the reactor could be used to support the cooling pump system in case the supply of auxiliary electricity is cut off. The control rods of the reactor were lowered to bring output level down to 20% of the normal output, but the engineers lowered too many rods, and this caused output to decrease too rapidly. Then, the reactor was very close to shutting down. So, they started to raise the control rods to bring the reactor back to normal. They kept raising rods until the power reached about 12%, and then, the power suddenly shot up to extremely high levels. Soon, overheating occurred and the water coolant began to evaporate. The engineers pressed the shutdown button, but the reinsertion of control rods increased the concentration of reactivity in the lower part of the reactor. Now, the power level of the reactor was 100 times higher than regular, and then the reactor began to explode and it blew off the upper radiation shield. The contents from the reactor core erupted outwards, and air from the outside reacted with the carbon monoxide gas in the reactor to start a fire which lasted for nine days. 

How They Fixed It and Some Lasting Effects
The damaged reactor was sealed off and 200 cubic meters of concrete was placed between the disaster site and the operational buildings. They let three of the six reactors run because there would be an energy shortage in the country. Then one of the reactors had a fire, and it was declared the reactor was damaged beyond repair. Chernobyl is now enclosed by a large concrete sarcophagus, which was built quickly to allow the continuation of the operation of the other reactors at the plant. Since this structure was built very quickly they did not build it very well so they are now trying to build a New Safe Confinement which was supposed to be built by 2005. Delays kept on happening since 2010 and now they are projected to finish it by 2013. The nuclear reactor in a power plant exploded and it spread nuclear radiation throughout Europe and some lasting effects. It caused many health problems for many people and many plantations had been contaminated. Two Chernobyl plant workers died on the night of the accident, and 28 other people died within a few weeks as a result of radiation poisoning. UNSCEAR said that apart from increased thyroid cancers, "there is no evidence of a major public health impact attributable to radiation exposure 20 years after the accident." The building of the reactor was badly damaged and 31 people were killed. The accident could have been prevented if a concrete shell was constructed to around the reactor, which is the way nuclear reactors are built in other countries. An estimated 6500 people may contract cancer because of the Chernobyl nuclear accident. In fact, many children in the regions around Chernobyl are suffering from thyroid cancer today. About 200 people were hospitalized because of exposure to the radiation. It is believed that the medical effects of exposure to nuclear radiation will only start to show many years after the incident, and some of the health problems that are associated with radiation exposure are skin diseases, birth defects, and cancer. 

Explosion at Japan
Relating Chernobyl to Japan Incident
“Nuclear experts have repeatedly stated that the Japanese situation cannot get as bad as Chernobyl,” says Michael Marshall. In Japan the name of the reactor that was damaged is Fukushima Daiichi. The major difference between the incident at Fukushima Daiichi and Chernobyl is that at Chernobyl it was caused by untrained personnel and it was caused by people trying to do an experiment. At Fukushima Daiichi there was an earthquake which caused the nuclear reactor to be damaged. The nuclear reactors at Fukushima Daiichi automatically shut down which was supposed to happen. But the cooling systems have repeatedly failed, which caused the cores of some of the reactors to overheat. This has led to explosions damaging the outer buildings and parts of the containment systems which prevents radioactive material from escaping the reactor. Staff at Fukushima Daiichi were running tests to find out how well they could cope with a temporary shutdown of the reactor's cooling system. The test went bad and there was a power surge. They tried to shut the reactor down before anything happen but they were unsuccessful. "For a few seconds it was generating thousands of times the normal power output," says Michael Bluck of Imperial College London. The heat from the nuclear reaction caused an explosion, which blew off the roof of the reactor vessel and the building that contained it. This exposed radioactive material into the atmosphere. Many fires started but these fires were put out in the next few hours, but one of the reactors burned for a couple more days and it spread even more radioactive material. Another difference is that the Chernobyl reactor was running, but at Fukushima Daiichi the reactors were automatically shut down when the earthquake hit. Some people say that we shouldn’t be worried and some people say that we should only be worried a little bit. I think we shouldn’t be worried because at Chernobyl the International Nuclear Event Scale, scaled it at a level 7, and at Fukushima Daiichi a French Nuclear Agency predict it to be a level 5 or 6. I think that Chernobyl will always be worse because it wasn’t caused by a earthquake or something it was caused by some scientists trying to do an experiment, and at Fukushima Daiichi it was caused by a natural disaster.

Sunday, December 12, 2010

Ionic compounds

By: Kamil Heerji and Jack Leonard

Power Bar
1. Calcium Phosphate – Ca3(PO4)2
2. Potassium Phosphate – K3PO4

Special K Protein Bar
3. Salt – Sodium Chloride - NaCl
4. Calcium Carbonate – CaCO3
5. Zinc Oxide – ZnO

Purina Beneful(dog food)
6. Potassium Chloride - KCl
7. Zinc Sulfate – ZnSO4
8. Manganese (II) Sulfate – MnSO4
    Manganese (III) Sulfate - Mn2(SO4)3
9. Copper (I) Sulfate – Cu2SO4
    Copper (II) Sulfate – CuSO4
10. Calcium Iodide – CaI2

Morton’s Iodized Salt
11. Potassium Iodide - KI

Centrum Performance Multivitamin
12. Magnesium oxide - MgO
13. Sodium selenide – Na2Se
14. Ammonium chloride – NH4Cl

Campbell’s Chicken Noodle soup
15. Ferrous (iron) sulfate – FeSo4
16. Sodium phosphate - Na3(PO4)

Clean and Clear Face Wash
17. Sodium hydroxide - NaOH
18. Iron oxide – Fe2O3

Sensodyne Tooth Paste
19. Potassium Nitrate – KNO3
20. Sodium Fluoride - NaF

Thursday, November 11, 2010

Exam Review

7.)Describe the different principles that govern the building of an electron configuration.

The Pauli Exclusion Principles states that the orbitals can only hold 2 electrons, and the electrons must have an opposite spin because, it minimizes repulsions between the electrons(can never have the same spin in one orbital).

The Aufbau Principle states that electrons occupy orbitals of the lowest energy first, for example the 4s orbital fills before the 3d orbital.

Hunds Rule says that if their are multiple orbitals the electrons have to fill 1 electron in each orbital before an orbital gets its second electron.

Tuesday, October 5, 2010

Cathode Ray Discovery of the Electron

J.J. Thomson was experimenting with the cathode ray tube and figured out there is a smaller particle than the atom. Then after his discovery scientist came up with the name electron for this particle smaller than the atom. Even though we discussed this in class I thought it would be interesting to dig  deeper into the experiment of the cathode ray tube. I have made a Prezi with the information I have found.

Thursday, September 9, 2010


I picked salt as my household product. I observed physical properties and some chemical properties. I used salt because everyone has salt in their house and I am pretty sure it will not cause an explosion of any sort.

Physical Properties
1. It is a clear to white color
2. It is a powder when not mixed with a liquid
3.Density is 2.16 g/cm
4. When I froze salt for 2 hours, nothing happen to the salt it stayed at its powder form
5. Its melting point is 800.8° C

Chemical Properties
1. I mixed salt with water and the salt dissolved and the water was still clear.This mixture became a homogeneous mixture. 

2. I had synthetic malt vinegar, which is like a dark brown color, and mixed
 it with salt. The vinegar became a little bit lighter and the salt completely dissolved. This mixture became a homogeneous mixture.
3. Then I mixed salt with Dawn antibacterial soap. Even when i stirred it the salt did not dissolve in the soap. This mixture became a heterogeneous mixture. 

4. When I heated up only salt the salt was still powder, but the color of the salt changed to a dark red. 

5. Then I heated up salt and vinegar on the stove. The vinegar boils faster with the salt inside the vinegar. Salt makes the boiling point of a liquid come at a lower temperature.

Citations of malting point and density: