Chemical Kinetics & Nuclear Chemistry

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    Which molecule is considered the intermediate and why? Which step is the rate-determining step and why?
    • A2B, because it does not appear in the overall reaction;
    • Step 1 is the rate-determining step because it is the slowest step in the mechanism
  2. Consider the reaction, aA + bB ---> cC + dD. For zero-order reactions, the formation of product C is __
    independent of changes of concentrations of any of the reactants, A and B
  3. For zero-order reactions, the rate = __
    k[A]0[B]0 = k

    The reactants have a constant reaction rate = to the rate coefficient (rate constant) k.
  4. What factors can change the rate of a zero-order reaction?
    only temperature
  5. For 1st-order reactions, the rate =
    k[A]1 or k[B]1

    has a rate that is proportional to only one reactant
  6. Radioactive decay is __ order
  7. For 2nd order reactions, the rate =
    • k[A]1[B]1 or 
    • k[A]0[B]2 = k[B]2  or
    • k[A]2[B]0 = k[A]2
  8. Units of k in
    zero-order reactions __
    1st-order reactions __
    2nd-order reactions __
    • M/s;
    • S-1;
    • M-1S-1
  9. Isotopes of the same element have the same amount of __ but differing numbers of __
    • protons; neutrons
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  10. A specific nucleus with a given atomic number and mass number is called a __. Protons and neutrons are known as __
    • nuclide;
    • nucleons
  11. The mass defect is __
    the difference between the mass of an isotope and its mass number
  12. The binding energy is the energy that __ and is equal to __
    • holds a nucleus together;
    • the mass defect of the nucleus
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  13. type of radioactive decay: A helium atom that has lost its 2 electrons
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  14. type of radioactive decay: high speed electrons
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  15. type of radioactive decay: very high energy photons, often released as nucleons. adjust from high-energy state to low-energy state
    γ(gamma) radiation
  16. positron
    β+, has the same mass as an electron but a positive charge
  17. radiation emitted & generic equation for for each decay type
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  18. The absorbed dose of radiation is the energy deposited in a sample (i.e. human body) when it is exposed to radiation. The SI unit is the
    gray (Gy) and corresponds to 1 J/kg
  19. The dose equivalent is the actual dose modified to take into account the different destructive powers of the various types of radiation in combination with various types of tissues. The SI unit is the
    • sievert (Sv)
    • Sv = Q x Gy

    (Q = relative biological effectiveness)
  20. The activity of a sample is the number of nuclear disintegrations in a given interval divided by the length of the interval. The SI unit is
    1 becquerel (Bq) = one nuclear disintegration per second
  21. Neutrons produced in a chain reaction are moving very fast, and most escape without colliding with another fissionable nucleus. If a large enough number of uranium nuclei are present in the sample, enough neutrons can be captured to sustain the chain reaction. This is called __
    critical mass: a mass of fissionable material above which so few neutrons escape from the sample that the fission reaction is sustained

    Critical mass can be compressed.
  22. A sample that __ is said to be subcritical.
    has less than the critical mass for its density
  23. Of the 2 types of nuclear weapons (gun-type and implosion-type), the __ is more powerful, because __
    implosion-type, it takes less mass to produce more power compared to the gun-type

    Little Boy (gun-type) produced 15 kilotons of TNT (63 TJ) while Fat man produced 21 kilotons of TNT (88 TJ)

    The Tsar Bomba is even more powerful than the Fat Man (57 megatons of TNT)
  24. Explosive fission reactions __ occur in a nuclear reactor, because __
    cannot; the fuel is not dense enough

    The fuel is shaped into long rods and inserted into a moderator, a material that slows down the neutrons as they pass between the fuel rods
Card Set:
Chemical Kinetics & Nuclear Chemistry
2017-03-04 05:39:54

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