Drill:•Calculate the solubility of MgF2 in 0.10 M KF.

•Ksp MgF2 = 6.4 x 10-9

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.

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.

Nuclear Chemistry

Nuclear Chemistry•The study of

reactions that take place in the nuclei

of atoms

Chemical Reactions•In normal chemical

reactions, only the electrons are

involved

Radioactive Nuclei

•Nuclei that spontaneously

decompose

Isotopes•Elements with the

same atomic number, but different mass

number

Isotopes•Elements with =

numbers of protons, but numbers of

neutrons

Isotopes•All elements have

at least one radioactive isotope

Nuclear Radiation•The emission of

particles & rays from spontaneously

decomposing nuclei

Modes of Decay•Alpha emission

•Beta emission

•Gamma emission

•Positron emission

•K-electron capture

Alpha Particle ()•Helium nucleus

•2 protons & 2 neutrons

•mass = 4 amu

•charge = +2

•Penetration power: small

Beta Particle ()•High speed electron

•1 electron

•mass = 1/1836 amu

•charge = -1• Penetration power: medium

Gamma Ray ()•High energy photon

•Electromagnetic wave

•mass = 0

•charge = 0

•Penetration power: great

Positron ()•Positive electron

•1 positive electron

•mass = 1/1836 amu

•charge = +1• Penetration power: medium

K-capture•The capture of an inner

level e- by the nucleus

•1 electron

•mass = 1/1836 amu

•charge = -1

Nuclear Symbol•Alpha: 2

4He or 24

•Beta: -10e or –1

0

•Gamma: 0 0

•Positron: +10e

•K-electron: -10e

Fission•The splitting of a nucleus into smaller nuclei involving the

release of energy

Fusion•The combining of smaller

nuclei into a larger nucleus involving the

release of energy

Drill:•Name &

describe 3 types of radiation

Fission•The splitting of a nucleus into smaller nuclei involving the

release of energy

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

Transmutation Rxns

•Nuclear reactions in which one

element is changed into another

Transmutation Rxns•Reactions in

which the nucleus of an atom is

changed

Transmutation Rxns

•Both fission & fusion are

examples of transmutation rxns

Transmutation Rxns•Can occur through

emission of or bombardment by

particles

Nuclear Symbol

•Alpha: 24He or

24

•Beta: -10e or –1

0

•Gamma: 0 0

Nuclear SymbolsNeutron

01n

Proton11p

Electron-1

0e

Transmutation Rxns emission of Pm-142

bombardment of Th-231

Transmutation Rxns emission

ofUfollowed by two

separate emissions:

Transmutation Rxns bombardment ofThfollow

ed by two separate emission:

Predict Products

emission of O-18 followed by a emission:

Predict Products absorption by V-

45 followed by neutron emission then emission

Predict Products neutron bombardment of Ta-182 followed by

emission then emission

Drill: Predict Prod Neutron absorption by Ufollowed by two separate

emission:

Nuclear Power

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

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

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 > 70%

Nuclear Fission• To create a chain reaction,

the U-235 % must be increased (enriched) greatly

• Ultra-centrifugation

Nuclear Fission Bomb

Decay Rate

The rate at which radioactive nuclei

break down

Half-Life The time it takes for

50 % of the radioactive nuclei to

decompose

Decay Rate Rate = kX/t

ln(Xi/Xf) = kt1/2

k = 0.693/t1/2

t1/2 = half-life

1st Order Age Dating Formula

ln(Xi/Xf)t1/2

0.693t =

Calculate the age of a skeleton found with 0.125 % C-14 when atmospheric C-14 =

1.00 %.

t1/2 C-14 = 5730 yr

Calculate the age of a tooth found with

0.00132 % C-14 when atmospheric C-14 =

1.00 %.

t1/2 C-14 = 5730

Drill:Predict the products in

each step when

Boron-12 goes through bombardment followed

by emission.

Predict the products in each step when

Uranium-234 goes through 5 straight

emissions.

Calculate the age of a bone found with

0.000010 % C-14 when atmospheric C-14 = 1.00 %. t1/2 C-14

= 5730

Mass-Energy Relations

E = mc2

Nuclear Fact The mass of any nucleus

is different than the sum of the masses of its protons & neutrons

Nuclear Fact The energy

corresponding to the mass difference can

be solved using:E = mc2

Binding Energy The energy that holds

a nucleus together corresponds to m of

nucleus

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 ray

Drill: Show neutron bombardment of

Ra-223 followed by 3 alpha emissions

•A fossil contained 3.125% of its original carbon-14. Determine its age.

•t1/2 for C-14 = 5730 yrs

Know the radioactive

particles & their characteristics.

Alpha ()Beta ()

Gamma ()

Know how to balance

transmutation reactions

Show the intermediates and the final isotope of alpha bombardment of

Xe-136 followed by two separate beta emissions.

Know how to perform age dating

ln(Xi/Xf)t1/2

0.693t =

Calculate the age of a bone found with

0.000010 % C-14

when atmospheric

C-14 = 1.00 %.

t1/2 C-14 = 5730

Know How to Determine

Reactions in an Electrolytic Cell

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.

Know how to make

electroplating calculations.

Charge (mass) =current x time

coul = amp x sec

q = It

Saul’s Rule

nFm = MWIt

Calculate the mass of Al purified from

Al2O3 using a current of 96.5 MA

for 5.0 hrs.

Calculate the time required to plate

1.08 g of silver onto a cathode using a

current of 965 mA.