Chemistry Notes
Chemistry Notes
Cracking:
* 2 types of Cracking; Catalytic cracking and Steam/thermal cracking. * Catalytic cracking, using a catalyst called Zeolite (Aluminosilicate), 500 degrees C, in the absence of air and at pressures just above atmospheric * Thermal cracking is done without a catalyst; steam is passed through very hot metal tubes at 700-1000 degrees C at just above atmospheric pressure. * This is used to break down longer chains of unsalable hydrocarbons into smaller salable hydrocarbons.
Polymers:
* Mer is the Greek word for unit, polymer is the term used to describe a substance made by joining many units together. * 2 classes of polymers based on how the mers are joined together. * Addition – mers joined without the loss of atoms (presence of unsaturated carbons). * Condensation – mers joined through the loss of atoms from the functional groups of each monomer.
Radioactive isotopes: * Everything with an atomic number over 82 is radioactive. * Unstable nuclei; too many neutrons:protons, large nuclei * Cobalt 60 formed by neutron bombardment.
Detection: * Photographic film – exposes film * Geiger counter – alpha particles ionize noble gas * Cloud chambers
Calibration Curve (AKA Standard Curve) * A number of Solutions (of known concentrations) containing the substance to be tested are prepared. * The absorbances of each of the solutions are measured (using the appropriate discharge lamp). * A standard plot is produced of absorbance verses concentration. * When an “unknown” solution is tested the absorbance is noted and applied to the standard graph with the concentration being read directly off the graph. Eg. Plot of absorbance verses concentration:
If the unknown solution has an absorbance of x, then the concentration will be y:
Describe the composition and Layered structure of the atmosphere
N2 78.08%
O2 20.95%
Ar 0.93%
CO2 0.2ppm
CH4 1.5ppm
H2
Cracking:
* 2 types of Cracking; Catalytic cracking and Steam/thermal cracking. * Catalytic cracking, using a catalyst called Zeolite (Aluminosilicate), 500 degrees C, in the absence of air and at pressures just above atmospheric * Thermal cracking is done without a catalyst; steam is passed through very hot metal tubes at 700-1000 degrees C at just above atmospheric pressure. * This is used to break down longer chains of unsalable hydrocarbons into smaller salable hydrocarbons.
Polymers:
* Mer is the Greek word for unit, polymer is the term used to describe a substance made by joining many units together. * 2 classes of polymers based on how the mers are joined together. * Addition – mers joined without the loss of atoms (presence of unsaturated carbons). * Condensation – mers joined through the loss of atoms from the functional groups of each monomer.
Radioactive isotopes: * Everything with an atomic number over 82 is radioactive. * Unstable nuclei; too many neutrons:protons, large nuclei * Cobalt 60 formed by neutron bombardment.
Detection: * Photographic film – exposes film * Geiger counter – alpha particles ionize noble gas * Cloud chambers
Calibration Curve (AKA Standard Curve) * A number of Solutions (of known concentrations) containing the substance to be tested are prepared. * The absorbances of each of the solutions are measured (using the appropriate discharge lamp). * A standard plot is produced of absorbance verses concentration. * When an “unknown” solution is tested the absorbance is noted and applied to the standard graph with the concentration being read directly off the graph. Eg. Plot of absorbance verses concentration:
If the unknown solution has an absorbance of x, then the concentration will be y:
Describe the composition and Layered structure of the atmosphere
N2 78.08%
O2 20.95%
Ar 0.93%
CO2 0.2ppm
CH4 1.5ppm
H2