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Chemathon 2009

Chemathon 2009

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Chemathon 2009

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  1. Chemathon 2009 Nugent

  2. 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

  3. 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

  4. Endothermic Physical Change

  5. A watched pot still boils Increasing IMFs  Increasing Molecular Polarity

  6. Gas laws P T

  7. Separation • Techniques • Filtration • Distillation • Evaporation/Boiling • Chromatography

  8. 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

  9. Saturated • Supersaturated • Unsaturated Gas: ↑ temp ↓ solubility Sol/liquid: ↑ temp ↑ solubility

  10. Calc: • Molarity (M) molessolute/literssolution/total • ppm: gramssolute/gramssolution

  11. Organic Rxns • Subsitiution: alkane + diatomicHX + halocarb • Addition: breaking =/≡ bonds (alkene/alkyne) • Combustion: org + O2 CO2 + H2O • Fermentation: C6H12O6 + __aseCO2 + alcohol • Saponification: fat + base = soap + glycerine • Esterification:alcohol(OH)+ acid(COOH)ester(COOC) • Polymerization (addition, condensation) • Monomer Polymer (many links)

  12. 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

  13. 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

  14. Redox • Always SR: Transfer of electrons • 3Mg0 + Al2+3S3 3Mg+2S-2(s) + 2Al0 • Oxidation: LEO, anode • Mg0 Mg+2 + 2 e- • Reduction: GER, cathode • Al+3 + 3e- Al0 • Anode  Cathode ALWAYS • Total e- gained must = total lost

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

  16. Ionic Equations • Covalent has dashes • Ionic has brackets • Mg + O  [Mg]+2[ O ]-2

  17. Electrochemical Cells

  18. ElectrolyticElectroplating  More Easily Reduced  More easily oxidized • Metal is Cathode

  19. 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).

  20. 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 acidic7 neutral8-14 basic (alkaline) • Table M • Litmus: pH changes color at 5.5-8.2 (0-5.5 Red) • Acid + Base  salt + water

  21. PT

  22. 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)

  23. 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

  24. 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)

  25. Equilibrium • Physical: Phase change Hf or Hv • Solution: CO2 g/aq or crystallization s/aq • Chemical: • Rate of forward rxn=rate of reverse • Concentrations remain constant

  26. Table N: DecayRemember: Nothing stops radioactive decay from happening! • 42α or 42He alpha (pos charge: He w/o e-) • Weakest penetrating power • Stopped by paper • 0-1β beta (neg charge, electron) • 00γ gamma, no mass or charge. • Strongest penetrating power • Needs lead or 12 inches of concrete to stop

  27. 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

  28. 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)