Chemistry day 8 Flashcards
gain of electrons
reduction
Loss of electrons
oxidation
elements in their elemental form
zero oxidations state
group one metals
+1
group 2 metals
+2
Hydrogen
+1 except when bonded to metals then -1..
Transition metals…
must be deteremined by anions charge… (Al=+3, Zn=+2, Cd=+2, Ag=+1)
most electrognegative elements get
their typical oxidation state
The last element not assigned balances….
balances the compound/ion
Oxidizing agent(oxidant)
species that is reduced
reducing agent(reductant)
speies that is oxidiezed
Elements or compounds are oxidized/reduced
entire chemical species act as the reducing/oxidizing agents
Anode
ALWAYs the size of oxidation…. an ox… electrochemical cell
Cathode… electrochemical cells
always teh site of recution RED CAT
Electrochemical Cells
Electrons always flow from anode to cathode
Anions flow to the…
anode and cations to the cathode through the salt bridge…
Galvanic/voltaid
(spontaneous) cells, the cathode is + and the anode is -
Electrolyic cell
non-spontaneous… the anode is + and the cathode is -
metal/metal salt solution cells
the cathode gains mass, while the anode loses mass
Voltaic cells
Battires E>0… Produce electricity …… Anode(-) to Cathode(+) species oxidized…
Standard Hydrogen Electrode SHE
potnetial of 0.00 V
Solid
can not effect shift in equillibrium
shift to the right…
higher potential
shift to the left
lower potential
Spontaneous Rxns
G0 Q<K
strongest oxidizing agent
most spontaneous
oxidized, reduced
product
Stable nuclei
even numbers of protons and or neutrons to be more stable
N/Z ration
Magic numbers are more stable (2,8,20,50,82,126)
Parent—>
daughter + energy
moss is always lost
E= mc^2
Alpha decay
reduces mass #… large nuclei below the belt
Beta deca (beta emission)
n—-> p N/Z is too hight… same net result 0/-1
B + decay (Positron emission)
0/4 p—>n…. N/Z too low
gamma decay…
excited state to lower state
the splitting of larger nuclei into smaller nuclei
fission
the combination of smaller nuclei into larger nuclei
fusion
Rate of Decay
Always first order (InN=lnNo-kt) natural log
half life…
t1/2= .693/k
amount of energy holding somethign together
mass defect
E=
mc^2
1g=
6.022X10^23 amu
Calculating nuclear biding energy
1 calculate mass defect (actual mass- predicted mass)
- convert to kg
- plug inot E=chang mc^2
- divide by # of nucleons (total of p+n; same as mass #)
