Chemathon 2009

Nugent

Matter Matter: mass and volume Pure substance: element/ 1 type of cmpd

Elements cannot be broken down by chemical change Compound: bonded elements, needs chemical

change Mixture: non-bonded grouping: min. 2

Broken down by physical processes Heterogeneous: uneven distribution Homogeneous: evenly dispersed

solution

Behavior of Matter Solid: close, high IMF, low PE/KE; low entropy,

rigid structure Liquid: medium, takes shape of container, but

not volume Gas: far apart, low IMF, High PE/KE, random.

Shape and volume of container. Variable volume.

Phase change=heat (in JOULES!) UNITS

Endothermic Physical Change

A watched pot still boils

Increasing IMFs

Increasing Molecular Polarity

Gas laws

P

T

Separation Techniques

•Filtration•Distillation•Evaporation/Boiling•Chromatography

Solution = solute + solvent

Solute: being dissolved Solvent: into this Properties:

Can be separated by evaporation Cannot be separated by filtering Particles are ions and molecules Particles so small they don’t reflect light Transparent

Saturated Supersaturated Unsaturated

Gas: ↑ temp ↓ solubility

Sol/liquid: ↑ temp ↑ solubility

Calc: Molarity (M) molessolute/literssolution/total

ppm: gramssolute/gramssolution

Organic Rxns Subsitiution: alkane + diatomicHX + halocarb

Addition: breaking =/≡ bonds (alkene/alkyne)

Combustion: org + O2 CO2 + H2O

Fermentation: C6H12O6 + __aseCO2 + alcohol

Saponification: fat + base = soap + glycerine Esterification:alcohol(OH)+ acid(COOH)ester(COOC)

Polymerization (addition, condensation) Monomer Polymer (many links)

Covalent Bonds Shared valence e- Non-polar: same atom N≡N (BrINClHOF) Polar: unequal sharing C-Cl

Lewis Dot:Two at the top, then work around.Don’t forget to draw unbonded val e-Every two shared dots = one dash

Covalent Molecules (whole thing) Asymmetrical: polar Symmetrical: non-polar

Even Distribution of electrons Shapes/Naming: ending to ‘ide:’ di, tri, tetra H2O

CO2

CX4

Diatomics

NH3

Redox Always SR: Transfer of electrons

3Mg0 + Al2+3S3 3Mg+2S-2(s) + 2Al0

Oxidation: LEO, anode Mg0 Mg+2 + 2 e-

Reduction: GER, cathodeAl+3 + 3e- Al0

Anode Cathode ALWAYS Total e- gained must = total lost

Ionic Bonding

Naming: 1st keeps name, 2nd end to ‘ide’ Total charge always ZERO Switch and Flip Use chart for endings like –ate, ite

Ionic Equations

Covalent has dashes Ionic has brackets Mg + O [Mg]+2[ O ]-2

Electrochemical Cells

ElectrolyticElectroplating

Metal is Cathode

More easily oxidized

More E

asily Reduced

Alternative Fuels:

Biodiesel: still pollutes, but uses matter that would produce greenhouse gasses anyway (no new pollutants)

Ethanol: corn alcohol. Also produces greenhouse gasses

Water is a greenhouse gas! And CH4 and CO2 Solar, geothermal, wind, hydroelectric do not

produce any pollution (except noise).

Acid/Base/Salt: Acid =H+ Base = OH-

Electrolytes pH=-log[H+] or –log[H3O+] :[ ]=M ↑ H+ ↓pH ↑ H+ ↓OH- ↑ OH- ↑pH Each step on pH= factor x10 (3 jumps = 1000x) 1-6 acidic 7 neutral 8-14 basic (alkaline) Table M Litmus: pH changes color at 5.5-8.2 (0-5.5 Red) Acid + Base salt + water

PT

Atomic Theory Cannonball: Dalton

Smallest (wrong –electrons, protons, neutrons) Indivisible (wrong- nuclear fission) One element: all identical atom (wrong- isotopes) Compounds: different atoms combined

Plum Pudding: JJ Thompson +/- charges Rutherford: empty space, small + core Bohr (electron shells: orbit in circles) Wave Mechanical (no fixed path:

orbital most probable location)

***Ave atomic mass: MAD! Multiply mass x %, add, /100)

SubAtomic Particles

Proton: 1 amu, in the nucleus, positive Neutron: 1 amu, in the nucleus, neutral Electron: 0 amu, around the nucleaus,

negative Mass number: protons + neutrons Isotopes: same # protons, different

neutrons

Kinetics and Equilibrium

Collision Theory Energy and spatial orientation (close and facing)

Reaction Rate: what speeds up a rxn Concentration Nature of Reactants Surface Area Temperature Pressure (gasses =concentration)

Equilibrium

Physical: Phase change Hf or Hv

Solution: CO2 g/aq or crystallization s/aq Chemical:

Rate of forward rxn=rate of reverseConcentrations remain constant

Table N: DecayRemember: Nothing stops radioactive decay from happening! 4

2α or 42He alpha (pos charge: He w/o e-)

Weakest penetrating powerStopped by paper

0-1β beta (neg charge, electron)

00γ gamma, no mass or charge. Strongest penetrating powerNeeds lead or 12 inches of concrete to stop

Nuclear Transmutations Mass and charge must be equal on both

sides Natural: Decay 1 2+ Atomic number 83+ Artificial: bombard 2 (fission) Mass converted to energy in fission/fusion ½ life chart: ½ lives:mass:total time:fraction

1 total 0 1 2 /2 add 1 HL 1/2

Uses of Nuclear Co-60 used for medical irradiation of tumors P-31 and Tc-99: radiotracers C-14: dating carbon based artifcact U-238 dating rocks, earth, inorganic I-131: treating thyroid disorders

Fission: splitting big atoms (nuc reactors) Fusion: H + H He (most energy:SUN)