Tuesday, May 17, 2011

Chemistry Review Questions

3.         Which two forms of compounds (ionic, covalent, metallic) can conduct electricity? Under what conditions can they conduct electricity and why?

Ionic and metallic bonds can conduct electricity.

Ionic compounds can conduct electricity when in a molten state or if dissolved. They can conduct electricity in these states because the electrons can move throughout the molten compound or in the solution formed. They cannot conduct when solid unless they are under the influence of an electric field.

Metallic compounds can conduct electricity only when they are molten or dissolved in a solution. When molten or dissolved the compounds’ electrons are free to move around and are able to conduct in these states. Electricity is able then to pass through the free electrons in the molten or dissolved substance.

31. CH.9 Test Review: Change in pH, how to find the grams needed to increase the pH of a solution.  (Thought this problem was a little hard at first, but once explained it can be very simple.)
9) How many grams of NaOH would be needed to make the pH of a solution increase from 10.000 to 12.000 using 500.0mL of the solution.


pH1 10.000 -> pOH 4.000
pH2 12.000 -> pOH 2.000
V .500 L

Solve for molarity of OH-:
pOH -> M OH+ (10^-pOH)

pOH1 = 1.000x10^-4 M OH-
pOH2 = 1.000x10^-2 M OH-

Solve for the moles of OH- of each:
mol = MV

mol OH1- = 5x10^-5
mol OH2- = .00500

Find the change of the # of moles:

(mol OH1-) - (mol OH2-) = .00495 mol OH-

Moles of OH- in NaOH is 1 mol OH-

.00495 mol OH- x 40g NaOH/1 mol OH- = 
.198g NaOH

Thursday, April 7, 2011

Chernobyl and Japan


            Chernobyl was a nuclear power plant located in the Ukraine. The disaster took place on April 26, 1986 at 1:23 am. The problem in the reactor was caused by a flawed reactor design with inadequately trained personnel. The inexperienced personnel took the power down and then tried to power it back up quickly to check whether a 40 second power gap in the cooling system could be bridged. The first night of the incident two plant workers died, another 28 died in the few weeks after the incident. 134 people were diagnosed with ARS or acute radiation syndrome. The accident at Chernobyl destroyed the Chernobyl 4 reactor.  Large areas of Belarus, Ukraine, and Russia and beyond were contaminated in varying degrees.

20 Years later

            Radiation from the disaster spread to parts of the western Soviet Union, Eastern Europe, Western Europe, Northern Europe, and eastern North America. Large areas in Ukraine, Belarus, and Russia were badly contaminated, resulting in the evacuation and resettlement of over 336,000 people. According to official post-Soviet data, about 60% of the radioactive fallout landed in Belarus. In some of those areas that were contaminated people were affected greatly. Children were born with several deformities and/or cancerous tumors.

25 Years later

            The area is currently fenced in an area known as the Exclusion Zone. Remnants, still radioactive, are still inside. The enclosure is a 24 story concrete and steel encasement, that was quickly built after the event, but is currently structurally unsound and threatens to collapse. If it were to fall, enough radiation would be released to cause a second disaster of similar consequences. A new structure has been planned to be built around the current enclosure to ensure radiation does not escape, but the price for this is estimated to be about 2 billion dollars.

Differences between Chernobyl and Japan

·        Chernobyl was a 3200 MV Reactor and the three reactors in Japan were 500 MV

·        Chernobyl exploded while it was working at peak capacity and the reactors in Japan were turned off successfully after the first tremors of the earthquake

·        Chernobyl was a Soviet RBMK-1000 reactor and the Japanese reactors were Boiling Water Reactors

·        Chernobyl was a new design undergoing tests while the reactors in Japan were proven to work well

Brief Summary of How Nuclear Reactor Works

            “The core of a nuclear reactor contains both water and fuel rods made of zirconium and pellets of nuclear fuel, such as uranium, that set off a controlled nuclear reaction. The reaction, heats the water, creating 550-degree Fahrenheit steam, which powers a turbine, generating electricity.”


            In some articles it describes the danger as being small. Only a small amount of radiation is currently being released from the damaged reactors in Japan. Once the reactors cool down, they can determine whether or not the cores are undamaged and whether or not people should be really worried.

latest news Japan nuclear reactors 300x207 Japans workers struggle to bring power back to Fukushima reactor
Works Cited

Casselman, Ben, and Rebecca Smith. “How Nuclear Reactors Work... And the Dangers When They Don’t.” The Wall Street Journal. N.p., 15 Mar. 2011. Web. 7 Apr. 2011. <http://online.wsj.com/‌article/‌SB10001424052748704893604576200982857244782.html>.
“Chernobyl Accident.” World Nuclear Association. N.p., Mar. 2011. Web. 7 Apr. 2011. <http://www.world-nuclear.org/‌info/‌chernobyl/‌inf07.html>.
“Chernobyl: 25 Years After The Nuclear Disaster (PHOTOS).” HuffPost Green. N.p., 7 Apr. 2011. Web. 7 Apr. 2011. <http://www.huffingtonpost.com/‌2011/‌02/‌02/‌chernobyl-25-years-after-_n_816902.html#s233577>.
Marquand, Robert. “Japan’s nuclear crisis and Chernobyl: key differences.” The Cristian Science Monitor. N.p., n.d. Web. 7 Apr. 2011. <http://www.csmonitor.com/‌World/‌Global-News/‌2011/‌0313/‌Japan-s-nuclear-crisis-and-Chernobyl-key-differences>.
Waldoks, Ehud Zion. “’Comparison between Chernobyl, Japan out of place.’” The Jerusalem Post. N.p., 15 Mar. 2011. Web. 7 Apr. 2011. <http://www.jpost.com/‌Sci-Tech/‌Article.aspx?id=212169>.

Saturday, January 22, 2011


                         Edible Covalent Compounds

Molecular Formula
Empirical Formula
Common Food
Carbon dioxide
Found in sodas
Acetic Acid
Found in vinegar
Drinking alcohol

                           Covalent Compound Haiku

Covalent compounds
Atoms sharing electrons
Balance of forces