Drill:

1
Drill

• Calculate the solubility of MgF2 in 0.10 M KF.
• Ksp MgF2 6.4 x 10-9

2
Drill A statue is electroplated at the cathode
using a silver anode in aqueous AgNO3. Calculate
the current required to plate 10.8 g of silver in
5.0 minutes.
3
Drill Calculate the volume of Cl2 formed at 27oC
under 75 kPa when xs molten NaCl is electrolyzed
with 96.5 mA for 5.0 mins.
4
Nuclear Chemistry
5
Nuclear Chemistry

• The study of reactions that take place in the
  nuclei of atoms

6
Chemical Reactions

• In normal chemical reactions, only the electrons
  are involved

7
Radioactive Nuclei

• Nuclei that spontaneously decompose

8
Isotopes

• Elements with the same atomic number, but
  different mass number

9
Isotopes

• Elements with numbers of protons, but ? numbers
  of neutrons

10
Isotopes

• All elements have at least one radioactive isotope

11
Nuclear Radiation

• The emission of particles rays from
  spontaneously decomposing nuclei

12
Modes of Decay

• Alpha emission
• Beta emission
• Gamma emission
• Positron emission
• K-electron capture

13
Alpha Particle (a)

• Helium nucleus
• 2 protons 2 neutrons
• mass 4 amu
• charge 2
• Penetration power small

14
Beta Particle (b)

• High speed electron
• 1 electron
• mass 1/1836 amu
• charge -1
• Penetration power medium

15
Gamma Ray (g)

• High energy photon
• Electromagnetic wave
• mass 0
• charge 0
• Penetration power great

16
Positron (p)

• Positive electron
• 1 positive electron
• mass 1/1836 amu
• charge 1
• Penetration power medium

17
K-capture

• The capture of an inner level e- by the nucleus
• 1 electron
• mass 1/1836 amu
• charge -1

18
Nuclear Symbol

• Alpha 24He or 24a
• Beta -10e or 10b
• Gamma 0 0 ?
• Positron 10e
• K-electron -10e

19
Fission

• The splitting of a nucleus into smaller nuclei
  involving the release of energy

20
Fusion

• The combining of smaller nuclei into a larger
  nucleus involving the release of energy

21
Drill

• Name describe 3 types of radiation

22
Fission

• The splitting of a nucleus into smaller nuclei
  involving the release of energy

23
Fusion

• The combining of smaller nuclei into a larger one
  involving the release of energy

24
Transmutation Rxns

• Nuclear reactions in which one element is changed
  into another

25
Transmutation Rxns

• Reactions in which the nucleus of an atom is
  changed

26
Transmutation Rxns

• Both fission fusion are examples of
  transmutation rxns

27
Transmutation Rxns

• Can occur through emission of or bombardment by
  particles

28
Nuclear Symbol

• Alpha 24He or 24a
• Beta -10e or 10b
• Gamma 0 0 ?

29
Nuclear Symbols

• Neutron 01n
• Proton 11p
• Electron -10e

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Transmutation Rxns

• b emission of Pm-142
• a bombardment of Th-231

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Transmutation Rxns

• a emission of U-238 followed by two separate b
  emissions

32
Transmutation Rxns

• a bombardment of Th-235 followed by two separate
  b emission

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Predict Products

• a emission of O-18 followed by a
• b emission

34
Predict Products

• b absorption by V-45 followed by neutron emission
  then a emission

35
Predict Products

• neutron bombardment of Ta-182 followed by b
  emission then a emission

36
Drill Predict Prod

• Neutron absorption by U-238 followed by two
  separate b emission

37
Nuclear Power
38
Nuclear Fission

• U-235 is the only fissable isotope of uranium
• 0.71 of uranium is U-235
• 99.28 of uranium is U-238

39
Nuclear Fission

• Chain reaction can occur only when it reaches
  critical mass
• The percentage of U-235 in uranium is too low to
  form a chain reaction

40
Nuclear Fission

• To run a power plant, the U-235 needs to be
  enriched to 2
• To make a bomb, the U-235 needs to be enriched to
  gt 70

41
Nuclear Fission

• To create a chain reaction, the U-235 must be
  increased (enriched) greatly
• Ultra-centrifugation

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43
Nuclear Fission Bomb
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Decay Rate

• The rate at which radioactive nuclei break down

45
Half-Life

• The time it takes for 50 of the radioactive
  nuclei to decompose

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Decay Rate

• Rate kDX/Dt
• ln(Xi/Xf) kt1/2
• k 0.693/t1/2
• t1/2 half-life

48
1st Order Age Dating Formula

• ln(Xi/Xf)t1/2
• 0.693

t
49

• Calculate the age of a skeleton found with 0.125
  C-14 when atmospheric C-14 1.00 .
• t1/2 C-14 5730 yr

50

• Calculate the age of a tooth found with 0.00132
  C-14 when atmospheric C-14 1.00 .
• t1/2 C-14 5730

51
Drill

• Predict the products in each step when
• Boron-12 goes through a bombardment followed by b
  emission.

52
Predict the products in each step
when Uranium-234 goes through 5 straight a
emissions.
53

• Calculate the age of a bone found with 0.000010
  C-14 when atmospheric C-14 1.00 . t1/2 C-14
  5730

54
Mass-Energy Relations

• DE Dmc2

55
Nuclear Fact

• The mass of any nucleus is different than the sum
  of the masses of its protons neutrons

56
Nuclear Fact

• The energy corresponding to the mass difference
  can be solved using
• DE Dmc2

57
Binding Energy

• The energy that holds a nucleus together
  corresponds to Dm of nucleus

58
In an atomic bomb, 40.00 kg of U-235 (235.401) is
split into Ba-143 (143.223) Kr-89 (89.335) 2
neutrons (1.014). A) Calculate the energy
released. B) Calculate the wavelength of the g
ray
59
Drill Show neutron bombardment of Ra-223
followed by 3 alpha emissions
60

• A fossil contained 3.125 of its original
  carbon-14. Determine its age.
• t1/2 for C-14 5730 yrs

61
Know the radioactive particles their
characteristics.
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Alpha (a)Beta (b)Gamma (g)
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Know how to balance transmutation reactions
64
Show the intermediates and the final isotope of
alpha bombardment of Xe-136 followed by two
separate beta emissions.
65
Know how to perform age dating

• ln(Xi/Xf)t1/2
• 0.693

t
66

• Calculate the age of a bone found with 0.000010
  C-14
• when atmospheric
• C-14 1.00 .
• t1/2 C-14 5730

67
Know How to Determine Reactions in an
Electrolytic Cell
68
2.0 volts is applied to a system through 2
platinum electrodes in an aqueous solution
containing ZnCl2(aq) CaBr2(aq).

• Calculate anode, cathode, total rxns
  voltages.

69
Know how to make electroplating calculations.
70
Charge (mass) current x timecoul amp x
secq It
71
Sauls Rule

• nFm MWIt

72
Calculate the mass of Al purified from Al2O3
using a current of 96.5 MA for 5.0 hrs.
73
Calculate the time required to plate 1.08 g of
silver onto a cathode using a current of 965 mA.