Sunday, May 15, 2011

Final Exam Review #17

How do you know if a double replacement reaction will occur?

  • a solid (precipitate) or gas must form (according to the solubility rules)
    1. All common compounds of Group I and ammonium ions are soluble.
    2. All nitrates, acetates, and chlorates are soluble.
    3. All binary compounds of the halogens (other than F) with metals are soluble, except those of Ag, Hg(I), and Pb. Pb halides are soluble in hot water.)
    4. All sulfates are soluble, except those of barium, strontium, calcium, lead, silver, and mercury (I). The latter three are slightly soluble.
    5. Except for rule 1, carbonates, hydroxides, oxides, silicates, and phosphates are insoluble.
    6. Sulfides are insoluble except for calcium, barium, strontium, magnesium, sodium, potassium, and (ammoniumhttp://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html)
  • it also occurs if an acid and a base create a salt and water
  • Example:  In the chemical equation below, according to the solubility rules the product copper (II) hydroxide is a solid and sodium nitrate is aqueous, therefore the double replacement reaction occurs.

    How do you know if a single replacement reaction will occur?
    • the single metal must be more reactive than the metal or non-metal in a compound
    • Use the activity series to see if element one is higher than element two in order for the reaction to occur, if not the reaction does not occur
    • Example: In the chemical equation below chlorine replaces bromine. Chlorine is higher than bromine on the activity series so the single replacement will take place.


    (http://www.avon-chemistry.com/ch9_chart11.jpg)

    Explain the process of using oxidation numbers to predict the product of a reaction.

    • oxidation numbers are used to find the number of the nonmetal "cations" to determine the polyatomic ion in the acid
    • it is not a real cation because cations are metals, but when I am referring to "cation" it is because we are looking for the negative charge of S which is a nonmetal

    If you have the equation SO2 +H20, in order to write the product of this combination you need to know the number of "cation" of S in the SO2.


    x= number of "cations" of the S (sulfur) which in this equation = 4
    The first two represents that there are two oxygens.  The -2 represents the charge of oxygen.  Lastly, the 0 represents the charge of the polyatomic ion which is nothing.

    Now use the same setup of an equation with sulfite and sulfate to see which has the same number of "cations" as SO2.  We use sulfite and sulfate because we know their "cations".



    Since SO2 and sulfite both have 4 as the number of "cations" of S, the balanced equation of the combination would look like:

    Sunday, March 27, 2011

    Nuclear Reactors and Chernobyl

    Demonstration of a Nuclear Reactor (4)
    Nuclear Reactors: (4)
    • Nuclear reactors contain and control chain reactions to produce energy (usually heat)
    •  Heavy neutrons and a small neutron sources are placed in the reactor vessel (tank)
    •  When the atom splits, it releases neutrons that causes another atom to split, creating a chain reaction
    • When an atom splits, it releases large amounts of energy in the form of heat
    • Next, the heat is carried out of the reactor by a coolant, water, and the coolant heats up and continues to a turbine to spin a generator or drive shaft
    •  There are several types of nuclear reactors because they include different fuels, coolants, fuel cycles, sand purposes
    •  Some examples are: pressurized water reactor, sodium cooled fast reactor, high temperature gas cooled reactor, and boiling water reactor


    The different parts: (4)
    •  Core- contains all of the nuclear fuel and generates all of the heat
    •  Coolant- can be water, heavy- water, liquid sodium, helium, or something that will perform the function to pass through the core, transferring heat from the fuel to a turbine
    •  Turbine- transfers the heat from the coolant to electricity
    •  Containment- structure that breaks apart the reactor and the environment (Chernobyl did not have a containment)
    • Cooling towers- where the power plant releases the excess heat that cannot be converted to energy


             
    The Nuclear Core (4)
    •    Fuel pins

    o   Smallest unit of the reactor
    o   Made of uranium oxide and surrounded by a zirconium clad to keep fission products from dodging the coolant
    (4)

    • Fuel assembly

    o   Bundles of fuel pins
    o   How fuel is put in and taken out
    o   Keeps the pins close, but not touching so the coolant touch all of the fuel pins
    (4)

    •  Full core

    o   Made up of hundreds of assemblies
    o   The assemblies vary in types of fuel and height
    (4)

    History of Chernobyl:




    (7)

    •  Chernobyl is a nuclear power plant in the wooded marshlands of the northern Ukraine (3)
    • The fourth reactor of the power plant began working in 1983 (3)
    • Pripyat was a small town built near Chernobyl to house its workers and their families (3)
    • April 25- 1986 at 1 a.m.: Chernobyl’s technicians shut down reactor four for maintenance and to run a test to see if during a power outage the turbines could produce enough energy to keep the cooling system running until backup generators started (3)
    •  The test was delayed because the nearby town, Kiev wanted their power
    • The test began again on April 26 at 1 a.m., but the reactor’s power dropped suddenly
    • The reactor went out of control and exploded at 1:23 a.m. (3)
    •  The explosion created a fire that lasted for ten days and spread radioactive fallout over tens of thousands of square miles (1)
    • The Soviet Union tried to keep the explosion a secret, but on April 28, the Swedish Forsmark nuclear power plant in Stockholm registered very high radiation levels near their plant (3)
    • The Soviet Union denied any information about a nuclear disaster to plants around Europe until 9 p.m. on April 28 when they proclaimed one of the reactors had been damaged (3)



    What went wrong at Chernobyl?
    •  While running the test, the operators turned off many of the safety systems which could have fixed the low power the reactor was experiencing, but instead the reactor when out of control and exploded (3)
    • The operators were too careless about the procedures of safety (2)


    What has been done to remedy the situation?
    •  In order to put out the fires, the Soviet Union poured water, sand, lead, and nitrogen on them for about two weeks until they were all put out (3)
    • They sealed contaminated topsoil in barrels (3)
    • Chernobyl Nuclear Power Plant is located in a fenced in area called the Exclusion Zone (1)
    • Around reactor four there is a 24- story concrete and steel encasement, a sarcophagus, to contain the radioactive remnants (1)
    • The sarcophagus is shaky and might collapse, so a plan for a new one to slide over the old encasement to seal in the remaining nuclear fuel is being planned, but it will cost about two billion dollars (1)
    • The new sarcophagus is estimated to be finished in 2013 (3)


    Lasting effects of the disaster:
    • The burning reactor created a cloud that spread various radioactive materials, especially iodine and caesim radionuclides (2)
    •  Radioactive iodine- 131 disintegrated during the first few weeks of the accident because of its short half life of 8 days (2)
    •  Caesium- 137 can still be measured in soils and some of the foods in parts of Europe because of its long half life of 30 years (2)
    • The largest deposits of radionuclides are found in Belarus, the Russian Federation, and Ukraine (2)
    •  31 people died right after the explosion and thousands are dying from the long term effects of radiation (3)
    • An environmental organization predicts more than 100,000 people have already died as the consequence of the disaster (1)
    •  It is predicted that 4,000 people will suffer a cancer- related illness because of the accident (1)
    • Quarter of a million people moved away permanently from their homes (1)
    •  Pripyat, the town that housed 50,000 plant worker is now a ghost town (1)
    •  In the abandoned villages, collapsed houses are disappearing under overgrowth (1)
    • There is now a greater search for alternative energy sources other than nuclear power (1)
    •  Since the Soviet had lied about knowing of the explosion of the reactor, there is a extensive distrust of official information and the mistaken acknowledgment of many ill health conditions to radiation exposure (2)



    Fun Facts:
    •  About 400 elderly people returned to their homes, ignoring the radiation levels (1)
    • Chernobyl accident is equivalent to 500 nuclear bombs used in Hiroshima in 1945. (6)
    • The releases contaminated an estimated 17 million people to some degree. (6)
    • 143,000 people have been evacuated from contaminated areas of Ukraine (6)
    • 600,000 people took part in liquidating effects of the disaster, 100,000 of which already died or are now handicapped (6)
    • Cases of leucosis and thyroid cancer exceed average by 2 and 5 times correspondingly among the Chernobyl victims. (6)
    • There are 1.8 million people residing on the territories of Ukraine, Russia, and Belarus, which are still defined as contaminated (6)
    • For the 14 years since the disaster 300,000 died in Ukraine alone from the radiation sickness (6)

    Chernobyl vs. Fukushima (5)
    Chernobyl (9)


    Fukushima (8)




    Similarities:
    •  Radiation lingered over a large area and a fallout cloud was created
    •  People evacuated their homes as soon as they heard the radiation was dangerous
    • The people who were exposed to the radiation gained different illnesses like cancer
    • Both disasters spread and affected many people


    Differences:
    • Other countries like America are working with Japan, while in Chernobyl the Soviet Union denied the explosion at first to other countries in Europe and did not receive help
    •  Chernobyl occurred because the operators were careless, while the nuclear power plant in Japan, Fukushima, exploded because of a few design flaws and the earthquake and tsunami that hit it
    • Chernobyl experienced more premature deaths than Fukushima
    • Fukushima's reactors are safer than Chernobyl's reactors because they were surrounded by steel and water


    Should we be worried?
    • No, radiation should not reach America
    •  There are people watching the radiation levels constantly
    •  Only issue would be if the supplies from Japan contained radiation, but the radiation level would be low enough that it will not affect humans
    • To be aware of, information on Fukushima is still being researched, and many people are worried that Japan is sending misleading information


    Work Cited

    2. http://chernobyl.info/Default.aspx?tabid=274




    6.http://www.chernobyl.com.ua/ChernobylFacts.htm

    7.http://www.google.com/imgres?imgurl=http://4.bp.blogspot.com/_AtLbLxyBasY/TFUwQseC_TI/AAAAAAAAAOc/c0tA6k9Ha2w/s400/Chernobyl.jpg&imgrefurl=http://devinder-sharma.blogspot.com/2010/08/chernobyl-disaster-killed-nearly-one.html&usg=__NMkK0PrUlCpLwrmAFj9vpuLmMhw=&h=300&w=400&sz=48&hl=en&start=79&sig2=zPW9qSkZyLKEvH1mQXeV0w&zoom=1&tbnid=OyYcjtHiHJbr3M:&tbnh=126&tbnw=168&ei=KMWPTZjrDsKftwfOnqGICQ&prev=/images%3Fq%3Dchernobyl%26um%3D1%26hl%3Den%26safe%3Dactive%26client%3Dsafari%26sa%3DN%26pwst%3D1%26rls%3Den%26biw%3D1104%26bih%3D594%26tbs%3Disch:10%2C2423&um=1&itbs=1&iact=rc&dur=365&oei=G8WPTZSiHcaJ0QGm-Li6Cw&page=6&ndsp=15&ved=1t:429,r:11,s:79&tx=139&ty=40&biw=1104&bih=594

    8. http://planetwaves.net/pagetwo/wp-content/uploads/2011/03/375+web-fukushima-damage.jpg

    9.http://upload.wikimedia.org/wikipedia/en/thumb/f/f6/Chernobyl_burning-aerial_view_of_core.jpg/220px-Chernobyl_burning-aerial_view_of_core.jpg

    Wednesday, January 26, 2011

    Fun with Chemistry Compounds

     3. Molecular Geometry
     Linear (looks like a roll of ribbon)

    Bent (looks like a book halfway open)
    Trigonal Pyramidal (looks like a bananas in a bunch)

    Trigonal Planar (looks like a hanger)




    Tetrahedral (looks like a back massager)

    4. Edible Covalent Compounds
    Name
    Molecular Formula
    Empirical Formulas
    Common food(s)
    Dihydrogen monoxide
    H2O       
    H2O
    water
    Citric acid
    C6H6O7
    C6H6O7
    lemons
    Acetic acid
    C2H4O2
    CH2O
    vinegar
    theine, mateine, guaranine,Caffeine
    C8H10N4O2

    C4H5N2O

    coffe, soda
    Monosaccharide, glucose
    C6H12O6
    CH2O
    sugar

    Friday, December 10, 2010

    Cosmetic Essentials with the Polyatomic Ions you NEED!


    By Marcy Applebaum and Emily Sher

    Revlon Age Defying All Day Lifting Foundation SPF 20, Cool Beige
    1.     zinc oxide  ZnO  
    2.     magnesium sulfate  MgSO4  
    3.     boron nitride  BN
    4.     iron (II) oxide  FeO
    5.     iron (III) oxide   Fe2O3


    Nair Lotion Hair Removal with Aloe and Lanolin
    6.     calcium hydroxide  Ca(OH)2
    7.     sodium hydroxide  NaOH 

    Cover Girl Perfect Blend Eye Pencil
    8.     calcium carbonate   CaCO3 

    Clearasil Stay Clear Daily Face Wash, Oil Free
    9.     sodium acetate   NaCH3COO
    10.sodium chloride  NaCl
    11. potassium hydroxide  KOH 


    Aquafresh Sensitive toothpaste
    12. sodium fluoride  NaF
    13.potassium nitrate    KNO3


    Avon Daily Oxygen Facial Cleanser
    14.magnesium nitrate   Mg(NO3)2
    15. potassium phosphate   K3PO4
    16. sodium phosphate  Na3PO4

    Dove Ultra Moisturizing Body Wash
    17. ammonium sulfate   (NH4)2SO4

    Clairol Herbal Essences, True Intense Color, Honey Fusion, 26- Moon Dance
    18. sodium carbonate  Na2CO3
    19. hydrogen peroxide  H2O2 

    Sally Hansen Teflon Tuff Nails French White Tip
    20. calcium fluoride   CaF2
    Cover Girl Clean Oil Control Liquid Makeup, Natural Ivory
    21. barium sulfate  BaSO4

    Tuesday, November 9, 2010

    Final Exam Review #9

    Explain which group in the periodic table has the highest electronegativity values? Why do noble gases tend to have electro negativities of zero?

    Halogens have the highest electronegativity values because as you move across to the right of the periodic table, the elements want to attract more electrons and protons to make the configuration more stable.  Halogens have the largest, greatest desire to attract one more electron to become a noble gas stable configuration.

    Green squares are the halogens
    http://www.bbc.co.uk/schools/gcsebitesize/science/images/38_modern_periodic_table.jpg
    Noble gases tend to have electro negativities of zero because they have a stable configuration and do not want to attract electrons when their atoms are in a stable compound.

    Sunday, October 3, 2010

    Discovery of the Proton


    <a href="http://www.wordle.net/show/wrdl/2530510/proton" 
        title="Wordle: proton"><img
        src="http://www.wordle.net/thumb/wrdl/2530510/proton"


    The Proton was discovered in 1918 by Ernest Rutherford when he sent alpha particles through nitrogen gas (7).  It is not always clear who discovered the proton because the process of the discovery  was slow and gradual, and many scientists contributed.  Thomson and Chadwick helped, but Rutherford is credited with the discovery because he was the first to clearly prove the existence of protons (8).

    Ernest Rutherford

    • originally from New Zealand, but moved to the UK to become a professor and teach future scientists (8)
    • won the Nobel Prize, was honored with knighthood, and overall became an icon (8)
    • because of the discovery of the proton he is referenced to as the "father of nuclear physics"(9)


    What is a proton?
    • a nucleon (9) that produces a positive electrical charge (1)
    • composed of two "up" quarks and one "down" quark (1)
      • a quark is an elementary particle (2)
      • gluons hold quarks together (4)
    • a subatomic particle found in the nucleus of an atom (7)
    • a proton can be bounded by nuclear force and converted to atomic nuclei (9)
    • a proton without neutrons is usually a nucleus of a common hydrogen atom isotope (9)
    The Experiment that proved the proton's existence:
    • Rutherford discovered the proton when he noticed the marks of hydrogen nuclei being released as the process of nitrogen was being converted into oxygen through a nuclear reaction involving the shooting of alpha particles into nitrogen gas (10)
    • Rutherford observed after shooting alpha particles into nitrogen gas that the scintillation (sparkle of light) detectors showed hydrogen nuclei indications that hydrogen could only have come from nitrogen (9)
    (10)
    • Rutherford concluded  nitrogen must be comprised of hydrogen nuclei
    •  He named the hydrogen nucleus, with atomic number one, proton (9), which is "first" in Greek (3)
    equation that explains nuclear reaction(10)

    nuclear transmutation taking place (turning an element into another)(10)
    • Rutherford performed another experiment where he shot alpha particles(helium nuclei produced by radioactive decay) at gold foil because he was trying to prove the model of an atom (4)
    • unpredicted from what he thought, some of the alpha particles passed through the gold foil, and others bounced back (4)
    • Rutherford recognized from his experiment that the alpha particles bounced back because the atom was made of a dense nucleus surrounded by a cloud of orbiting electrons (4)

    • once the electron was discovered, Rutherford reasoned that there were positive charge centers within the atom to balance the negative electrons and create electrically neutral atoms (6)
    • Rutherford's discovery of the nucleus proves that the positive charges were concentrated in a very small fraction of the atom's volume (6)
    • Rutherford and other physicists compared the nuclear masses to charges and realized that the positive charge of any nucleus could be accounted for by an integer number of hydrogen nuclei (6)
    • Video for clearer explanation of the gold foil experiment(proved protons were positive charged particles) below



















    (11)

    Importance that came from the discovery of the proton:
    • milestone in the development of atomic theory because it provided a greater understanding of how molecules bond and work (7)
    • Rutherford discovered he could change one element into another by striking it with energetic alpha particles, helium nuclei, where in each case the helium nuclei were released in the process (6)
    • number of protons in the nucleus of an atom determines which chemical element the atom is (7)
    Fun Facts:

    • scientists believes a proton lives for at least 10^31 years (2)
    • the Large Hadron Collider(LHC) is the world's most powerful particle accelerator and can smash protons (5)
    • In 1920 protons first appeared in print(newspapers, magazines) (6)

    Work Cited
    1. http://www.physicsoftheuniverse.com/scientists_rutherford.html
    2."Proton." Columbia Electronic Encyclopedia, 6th Edition (2009): 1. Vocational and Career Collection. EBSCO. Web. 30 Sept. 2010.
         3."Chadwick Proves the Existence of the Neutron." 379. Salem Press/Magill Books, 1999. Science Reference Center. EBSCO. Web. 30 Sept. 2010.
         4."Holey grail." Economist 367.8319 (2003): 72. MAS Ultra - School Edition. EBSCO. Web. 30 Sept. 2010.
         5. Castelvecchi, Davide. "Bring it on!." New Scientist 193.2588 (2007): 36. Science Reference Center. EBSCO. Web. 30 Sept. 2010.
         6.http://www.physlink.com/education/askexperts/ae46.cfm
         7.http://www.ehow.com/facts_5183474_discovery-proton-neutron.html
          8. http://www.articledashboard.com/Article/The-Story-of-The-Proton-Discovery-and-the-People-Behind-it/1580858
         9. http://www.everydayguide.com/who-discovered-the-proton/
         10. http://library.thinkquest.org/27954/proton.html
         11. http://www.youtube.com/watch?v=bSEOOMs5VNU

    Sunday, September 5, 2010

    Physical and Chemical Properties of Heavy Whipping Cream

    The object I chose was heavy whipping cream.
    I chose this object beacause I was curious how it would react to other mixtures.

    Physical Properties:


    • creamy white
    • liquid
    • homogeneous mixture
    • in each experiment I used 60 mL
    • low viscosity
    • odor is not strong but smells like milk

    30 ML x 2 = 60 ML
    flows fast


    Chemical Properties (Experiments):
    1. Mix in blender on speed 4 (medium speed) for 10 minutes
      before mixed
      after mixed
    • thickens into clumps, squishy, slimy
    • Chemical changes occurred when the composition changed to a solid and once the cream was mixed for a few minutes the mixture became a little warmer (exothermic reaction)
    • I performed this experiment because I hoped the cream would turn into a solid and maybe heat up, but it only became a little warmer (a little cooler than room temperature)
    2. Add 30 ML of vinegar and stir.
    • thickened
    • I added vinegar to create a chemical change because I hoped it would change colors, since vinegar is an acid, but it did not.
    • A small chemical change occurred when the mixture thickened because the composition changed





      left is before vinegar and right is with vinegar















    3. Add 30 ML of lysol cleaner and stir.
    after lysol was added
    • became a very thin liquid (lower viscosity than original)
    • became whiter with soap bubbles
    • I used Lysol because it is 3-4 % potassium hydroxide(http://en.wikipedia.org/wiki/Lysol) which is very exothermic in water (http://en.wikipedia.org/wiki/Potassium_hydroxide).
    • I hoped the chemical changes that would occur would be the transfer of heat (exothermic reaction) and a change in color because Lysol contains acid.
    • A chemical change did occur because the cream's composition changed into a thin bubbly mixture and the color changed to white rather than creamy white.
    4. Add 30 ML of sink water and stir.
    • I added water because I hoped a new, more liquid like composition would be created and the color would change.
    • The chemical changes which occurred were the variation of a more white color and the mixture changing composition to a more liquid state.
    • It is possible the mixture could have reacted differently to distilled water because the sink water has chemicals in it
    5. Add 20 ML of salt and stir
    • thickended immediately
    • salt absorbed cream and created clumps on the bottom
    • tastes salty
    • I picked salt because I hoped it would absorb in the heavy whipping cream and create a new composition.
    • The chemical properties were salty taste and the result of a new composition.
    • It is possible the mixture could have reacted differently if I used sodium instead of table salt because table salt has other elements mixed in it.
    Conclusion:
    I learned how butter is formed. By whipping and adding table salt the cream becomes the solid state of butter.