Term
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Definition
A: Mass number, number of electrons and neutrons
B: Atomic Number, number of protons
number of electrons is usually equal to protons |
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Term
| Maximum number of electrons per orbital |
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Definition
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Term
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Definition
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Term
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Definition
| The minimum energy required (to be added to the atom) to remove the outermost electron from the ground state of an isolated (eg. gaseous) atom |
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Term
| In what directions Ionisation Energy increases/decreases |
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Definition
Decreases from top to bottom
Increases from left to right |
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Term
| Three properties of ionisation energy |
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Definition
-Increases as successive electrons are removed
-Sharp increase when an inner-shell electron is removed
-High values of IE are why only valence electrons are involved in bonding |
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Term
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Definition
| The energy change that occurs when an electron is added to a gaseous atom - measures attraction of atom for the added electron |
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Term
| Properties of Electron Affinity |
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Definition
-Typically, energy is released when an electron is added (negative value)
-Typically increases (more negative) left to right
-Noble gasses are positive
-typically is positive (energy gained) when the added electron begins a new shell (eg. noble gasses, Be, Mg) |
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Term
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Definition
| The ability of an atom in a molecule to attract electrons to itself |
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Term
| In what directions Electronegativity increases/decreases |
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Definition
Increase from left to right
Decrease from top down |
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Term
| Describe Hydrogen Bonding |
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Definition
when the molecules in a molecular compound have both a hydrogen atom and at least one "lone pair" of electrons, the hydrogen of a molecule will be strongly attracted to the lone pair on an adjacent molecule, creating above average inter-molecular force.
http://chemwiki.ucdavis.edu/Physical_Chemistry/Quantum_Mechanics/Atomic_Theory/Intermolecular_Forces/Hydrogen_Bonding |
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Term
|
Definition
F = V - (N + B/2)
V = Valence Electrons
N = Non-Bonding Electrons
B = Bonding Electrons |
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Term
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Definition
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Term
|
Definition
Molecular
Covalent Network
Ionic
Metallic |
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Term
| Properties of Molecular Solids |
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Definition
-Intermolecular forces are weak
-Thus low melting point
-Room temperature gases and liquids usually form molecular solids at low temperature |
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Term
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Definition
| well-ordered, definite arrangements of molecules, atoms or ions. Crystals have an ordered, repeated structure |
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Term
|
Definition
no ordered structure,
e.g. rubber, glass |
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Term
| Properties of Covalent Network Solids |
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Definition
-Atoms held together in large networks by covalent bonds
-Examples: diamond, graphite, quartz (SiO2), silicon carbide (SiC), and boron nitride (BN) |
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Term
|
Definition
-Example of covalent network
-Long cylindrical structures
-Either single or multi walled
-Potential structural applications in high strength materials
-Applications in a range of conductive materials |
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Term
| Properties of Ionic Solids |
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Definition
-Regular structures, packing of positive and negative ions around each other
-Hard, brittle, high melting points
-Poor electrical conductors |
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Term
| Properties of Metallic Solids/Bonding |
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Definition
-Metal ions in a sea of delocalised valence electrons --> good electrical conductor
-Strong bonding
-Without any definite directions for bonds, the metals are easy to deform |
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Term
| coordination number of simple cubic, body-centred cubic and fcc |
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Definition
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Term
| occupation of simple cubic, body-centred cubic and fcc |
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Definition
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Term
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Definition
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Term
| Examples of body-centred cubic |
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Definition
| Ba, Cr, Fe, W, alkali metals |
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Term
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Definition
| For example: Ag, Al, Au, Ca, Cu, Ni, Pb, Pt |
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Term
| Images of cubic unit cells |
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Definition
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Term
| For CCP, the stacking pattern that produces hexagonal close packing |
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Definition
ABABABAB,
rather than ABCABCABCABC for Cubic Close Packing |
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Term
| picture of hexagonal close packing |
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Definition
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Term
| The two packing types for FCC |
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Definition
Hexagonal close packing
Cubic close packing |
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Term
| Differences between Hexagonal close packing and Cubic close packing |
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Definition
Cubic: Ductile
Hexagonal: Brittle |
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Term
| Properties of Metals vs Non-Metals |
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Definition
Metals:
-Low ionisation energy rather than High
-Malleable rather than usually brittle
-Good electrical conductors |
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Term
| about heterogeneous alloys |
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Definition
| components not dispersed uniformly |
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Term
| Two types of Solution alloys |
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Definition
-Substitutional alloys - solute atoms disperse main atoms
-Interstitial alloys - solute atoms occupy empty space between main atoms |
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Term
| about Substitutional alloys |
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Definition
-All atoms radius within 15% of each other
-Elements must have similar bonding characteristics
-Elements Must have same crystal structure
-Elements Must have Similar Electronegativity |
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Term
| about Interstitial alloys |
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Definition
| -One element must have a significantly smaller radius than the other |
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Term
|
Definition
P and T at which all three phases
are in equilibrium |
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Term
| what is abnormal about water phase diagram |
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Definition
| the solid-liquid line goes backward (i.e. solid is less dense than liquid) |
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Term
| what is a supercritical fluid |
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Definition
| a fluid that is beyond the temperature and pressure of the critical point. has a density of liquid and viscosity of gas. |
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Term
explain the steps:
[image] |
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Definition
| Energy is released by the changing of bonds as the iron changes phase, and so the material does not overall cool down at during these phase changes. |
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Term
| how to read binary phase diagram (picture) |
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Definition
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Term
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Definition
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Term
|
Definition
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Term
|
Definition
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Term
| basic steps for making portland cement |
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Definition
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Term
|
Definition
-Reaction of clinker materials with water to give gelatinous calcium silicates, solid Ca(OH)2, complex silicates, calcium aluminates, etc
-In concrete, the hydrated materials bind to solid aggregates (stones)
-Hydration reaction of Portland cement results in hardening
-There are rapid reactions within hours, and slow reactions over years |
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Term
| a few examples of things made from petroleum/crude oil |
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Definition
-liquid Fuels
-plastics
-detergents
-soaps
-drugs |
|
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Term
| picture of crude oil reservoir |
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Definition
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Term
| Elements/percentages in petroleum |
|
Definition
-Carbon 84%
-Hydrogen 14%
-Sulfur 1-3%
-Nitrogen, oxygen, metals, salts <1% each |
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Term
| Hydrocarbons in petroleum |
|
Definition
-Alkanes ~30%
-Cycloalkanes ~50%
-Aromatics ~15% |
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Term
| General formula of alkanes |
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Definition
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Term
| the three basic steps of crude oil before final use |
|
Definition
-Washing/desulfurisation: REMOVAL OF SALTS AND MINERAL CONTAMINANTS
-Seperation: Fractional Distillation
-Conversion: Reforming, Cracking, Alkylation and Isomerisation |
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Term
| Details of fractional distillation |
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Definition
| Crude oil is heated to ~600C and blasted into a distillation tower. The fuels come out in broad fractions based on number of carbons |
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Term
| Basics of the four conversion processes |
|
Definition
-Reforming: changes alkanes and cycloalkanes to more valuable aromatics (reformer)
-Cracking(Pyrolysis): breaks large hydrocarbons to smaller ones (coker)
-Alkylation: Changes alkanes and alkenes to larger branched alkanes (alkylation unit)
-Isomerisation: Alters arrangement of atoms in molecule |
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Term
|
Definition
-Uses heat, pressure and a catalyst
[image] |
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Term
| schematic of reforming unit |
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Definition
|
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Term
|
Definition
Catalytic cracking
Hydrocracking
Steam/Thermal cracking |
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Term
|
Definition
-Catalysts help reactions
-Typically ~900C and 10-20psi
-Three basic functions:
--Reaction of catalyst and feedstock cracks feedstock into different hydrocarbons
--catalyst is reactivated by burning off coke
--new hydrocarbons are distilled into different weights |
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Term
| Example chemical reaction of catalytic cracking |
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Definition
| C15H32 --> 2C2H4 + C3H6 + C8H18 |
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Term
| about fluid catalytic cracking |
|
Definition
-Feedstock is vaporised and mixed with a fluidised powdered catalyst (very very fine behaves like liquid)
-Carbon is deposited ON the catalyst, requiring it to be "regenerated" occasionally
-Modern implementations use a continuous loop system so the process can run while catalyst is regenerated |
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Term
| schematic of fluidised-bed cracking plant |
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Definition
|
|
Term
|
Definition
-Uses elevated partial pressure of hydrogen gas and catalysts
-Pressure of 1000-2000 Psi
-Temperature of 400-800 C
-Produces only saturated products |
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Term
| about thermal/steam cracking |
|
Definition
-Hydrocarbon diluted with steam and briefly heated in furnace without O2
-850°C, slightly above atmospheric pressure
-Residence time very short in reactor # milliseconds |
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Term
|
Definition
-Uses strong acid catalyst (sulfuric or hydrofluoric acid) and temperatures 0-30C
-High ratio of alkane to alkene
-Upgrades low molecular weight alkanes and alkenes to branched alkanes with increased molecular weight |
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Term
| Example equation of alkylation |
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Definition
|
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Term
|
Definition
-rearrangement of straight chain alkanes to branched alkanes
-Uses hydrogen, chloride and catalyst
-creates extra alkane feed for alkylation
-improves the octane of straight run alkanes |
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Term
| example euqation of isomerisation |
|
Definition
|
|
Term
|
Definition
| Fuel is any material that is burned or altered to obtain energy to do work through a chemical reaction. |
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Term
|
Definition
6 classes: class 1(light) to 6(heavy)
light/heavy as in length of carbon change and increase in boiling point and viscosity |
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Term
| about virgin/straight-run gasoline |
|
Definition
| not suitable for modern engines, but is the main part of the fuel blend |
|
|
Term
| the four stroke gasoline cycle (image) |
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Definition
|
|
Term
| define is compression ratio |
|
Definition
is equal to V/v,
V = Volume of cylinder at the bottom of the cyle
v = volume of the cylinder at the top of the cycle |
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Term
|
Definition
-Increases efficiency, somewhat logarithmically
-Modern cars R = ~9:1
-High compression ratio means fuel/air can spontaneously ignite --> knocking
-knocking prevented by high octane fuel |
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Term
|
Definition
-ON measures a fuel's resistance to auto-ignition
-modern cars require ON>~90 |
|
|
Term
| what is octane rating of straight-run gasoline |
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Definition
|
|
Term
| how Octane Number is measured |
|
Definition
-Measured in a test engine
-iso-octane has the benchmark ON of 100
-n-heptane (plain C7H16) has ON of 0
e.g. gasoline with the same knocking characteristics as a mixture of 90% iso-octane and 10% heptane would have an octane rating of 90 |
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Term
| how octane ratingincreases for different hydrocarbans |
|
Definition
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Term
|
Definition
Anti-knock
Lead replacement
antioxidants
de-icers
rust inhibitors |
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Term
| about anti-knock additives |
|
Definition
-lead is a cheap anti-knock additive, but obvious health dangers AND incompatibility with catalytic converters
-lead replaced by hydrocarbons of higher octane rating |
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Term
| about antioxidant additives |
|
Definition
-often amines
-prevent build up of gum, which can lead to engine damage and performance decrease |
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Term
|
Definition
-opposite of octane number
-measures ease at which fuel will undergo compression ignition
-for typical use CN = ~50 |
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Term
| approximate carbon chain length of gasoline |
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Definition
|
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Term
| approximate carbon chain length of diesel |
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Definition
|
|
Term
| what is biodiesel primarily made of |
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Definition
| triglycerides - triesters of glycerol with 3 long chain fatty acids |
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Term
| reaction for production of biodeisel |
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Definition
TRANSESTERIFICATION
triglyceride + Methanol --> Biodiesel + Glycerin |
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Term
| advantages/disadvantages of biodiesel |
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Definition
-Works in most diesel engines, Sustainable, less pollutants than fossil fuel, safer to handle than fossil fuels
-Can be problematic in some engines, lower fuel economy than fossil fuel |
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Term
|
Definition
Can be used pure of blended with petroleum
"B-factor":
100% biodiesel is referred to as B100;
20% biodiesel = B20 |
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Term
|
Definition
| Substance containing a tremendousamount of poten0al energy stored in chemical bonds. |
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Term
|
Definition
rapid release/expansion of gasses -> pressure
production of heat
quick release of energy
produces more stable substances (mainly gasses) |
|
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Term
| difference between fuels and explosives |
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Definition
Fuels react in a controlled manner
explosives react rapidly and violently |
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Term
| define high explosive. examples |
|
Definition
speed of reaction is faster than the speed of sound
Dynamite, TNT, plastic explosives |
|
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Term
| define low explosive. example |
|
Definition
speed of reaction slower than speed of sound
Black Powder |
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Term
| Two useful specification tests for explosives, units |
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Definition
Explosive Strength (cal/qty)
velocity of Detonation (m/s) |
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Term
| Trauzl test - brief description |
|
Definition
10g of explosive is placed in a cavity in a lead block, covered with sand and then detonated.
Resulting volume of cavity is compared to the Standard Volume produced by gelignite |
|
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Term
| basic methods of determining velocity of detonation |
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Definition
|
|
Term
| an explosive may consist of either: |
|
Definition
a chemically pure compound
a mixutre of fuel and oxidzer |
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Term
|
Definition
| ammonium"nitrate,"sodium"nitrate,"calcium"nitrate |
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|
Term
| two necessary structural features of molecular explosives |
|
Definition
at least on chemical bond that can easily be broken
A high proportion of oxygen required for explosion within the molecule itself |
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|
Term
| examples of weak bonds for molecular explosives |
|
Definition
|
|
Term
|
Definition
indicates degree to which an explosive can be oxidised
-Zero: exactly enough oxygen
-Positive: more than enough oxygen
-Negative: Not enough oxygen
Maximum explosiveness as oxygen balance approaches zero |
|
|
Term
| how to tell if reaction has positive or negative oxygen balance |
|
Definition
Pos: O2 produced
Neg: C or CO produced |
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|
Term
| about primary explosives. Example |
|
Definition
-Very powerful
-Very sensitive
-Usually used as only a detonator
-Mercury Fulminate |
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|
Term
| About Secondary Explosives. Example |
|
Definition
-aka high explosives
-Most explosives are secondary explosives
-nitroglycerin
-PETN - Benchmark. More explosive than PETN in primary explosive
-RDX
-Semtex |
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|
Term
| About tertiary explosives. Example |
|
Definition
-Not explosive unless mixed with other combustibles.
-Inexpensive
-must be detonated by secondary explosives
-ANFO (Ammonium Nitrate + Fuel Oils) |
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Term
| Use of explosive mixture allows control of |
|
Definition
-Strength
-V.O.D.
-Cost
-Safety |
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Term
|
Definition
made up of many repeating monomers.
High molecular weight |
|
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Term
|
Definition
| the process of linking monomers |
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Term
|
Definition
-Ease of processing
-Light Weight
-Tough
-Low Friction
-Flame retardant
-Insulating
-Appearance
-Weather/chemical resistance |
|
|
Term
| how increasing polymer chain length affects physical properties |
|
Definition
as chain length increases:
-melting and boiling point increase
-impact resistance increases
-viscosity increases
-chain mobility decreases
-strength and toughness increase |
|
|
Term
| how polymer branching affects physical properties |
|
Definition
can be linear, branched, cross-linked
affects chain packing and polymer density |
|
|
Term
| how interchain interactions affects physical properties |
|
Definition
-Interaction of chains through hydrogen bonding etc,
-rotation of carbon bonds
-affects strength and rigidity |
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Term
| about polymer non-uniform/disordered packing |
|
Definition
-amorphous
-less rigid - malleable
-weaker |
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|
Term
| about polymer crystalline packing |
|
Definition
- crystalline-like
-increased regidity, strength and opactity
-more brittle |
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Term
|
Definition
| vulcanisation: to natrual rubber heat and add sulfur. sulfur cross-links to make more rigid. 30% cross-linking is very rigid rubber. |
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|
Term
| Glass transition temperature |
|
Definition
| the temperature at which the transitionin the amorphous regions between glassy and rubbery occurs |
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Term
| How chain mobility affects Tg |
|
Definition
| more immobile chain --> higher Tg |
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|
Term
| How chain length affects Tg |
|
Definition
| Tg increases with increasing chain length |
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Term
|
Definition
-can be added to a polymer
-increase rubberyness of polymer
-decreaes Tg |
|
|
Term
|
Definition
| side chains are randomly distributed |
|
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Term
|
Definition
| side chains are all on the same side |
|
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Term
|
Definition
| side chains are on alternating sides |
|
|
Term
| five factors affecting Tg: |
|
Definition
-stiffer chain groups raise Tg
-strong intermolecular forces raise Tg
-side group restrict rotation, raise Tg
-cross linking raises Tg
-plasticisers lower Tg |
|
|
Term
| how to identify addition polymer |
|
Definition
| the repeating unit is always the same as the monomer from which the polymer is made |
|
|
Term
| The four addition polymerisation procedures |
|
Definition
-Radical Polymerisation
-Cationic Polymerisation
-Anionic Polymerisation
-Coordination Polymerisation |
|
|
Term
| General characteristics of radical addition polymerisation |
|
Definition
-Polymer chains form rapidly
-Extremely Exothermic
-Branching and cross-linking is common |
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Term
|
Definition
| polymer with more than one repeating monomer |
|
|
Term
|
Definition
| different monomers are distributed randomly |
|
|
Term
|
Definition
different monomers are alternating
ABABABABABABAB |
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|
Term
|
Definition
different monomers occur in blocks
AAAAAABBBBBBBAAAAAAAAAAAAAAABBBBBAAA |
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Term
|
Definition
| one monomer is main chain, another is a side chain |
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Term
|
Definition
|
|
Term
| about SBR Styrene Butadine Rubber |
|
Definition
-tyres, chewing gum
-replacement for natural rubber |
|
|
Term
| applications of polyamides |
|
Definition
-heat resistant
-strong synthetic fibres
-aerospace
-military
-kevlar |
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Term
|
Definition
-strongest known adhesives
-chemical and heat resistant |
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Term
|
Definition
| slowly begin to cross-link, so time to shape around teeth |
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|
Term
| about thermoplastic polymers |
|
Definition
-can be heated to softening without degradation
-not cross-linked
-difunctional monomers |
|
|
Term
| about thermosetting polymers |
|
Definition
-very hard and rigid once formed
-degrade when melted
-highly cross-linked |
|
|
Term
| examples of thermoplastics |
|
Definition
|
|
Term
|
Definition
-made from renewable biomass
can degrade... |
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