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31 Cards in this Set
- Front
- Back
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Rf=
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Rf= distance moved by component/ distance moved by the mobile phase front
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stationary phase in pap chrom
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the porous paper
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mobile phase in pap chrom
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the liquid pulled by capillary action
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like dissolves like
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polar dissolves polar more polar will travel farther. Larger Rf=more polar
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Vr= retention volume=
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vol of mob phase required to carry component through system.
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large Vr= in liquid chrom
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the better a given substance sticks to the stationary phase.
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to get good separations maximize
in chrom |
the component migration differences of the mobile and stationary phases.
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to get good separations minimize in chrom
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min the particle size of a solid stationary phase thus minimizing spreading during process done by
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mobile phase in gas chrom
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carrier gas, the natural gas Methane.
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Stationary phase in gas chrom
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dry tide detergent
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retention times gas chrom
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time between injection and when the center of component band
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factors that effect retention times
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temperature, volatility, affinity to the column, flow rate, and instruments parameters.
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CFC vs HFC
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CFCs are chloroflourocarbons
HFCs are hyrdoflourocarbons |
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Which is being phased out CFC or HFC?
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CFC as they destroy ozone which is important in the atmosphere.
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Practical apps of Gas Chrom
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trace pollutants in the air, pertroleum prods, barbotuates, drugs in blood breath saliva, flavors in food,
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Gas thermom
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measures temp by variation in vol or pressure of gas
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Charles Law
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V1/T1=V2/T2
as vol of gas went down, the temp thermom is less sensitive so the rang is wider. |
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3 reasons silicon temp is better than Hg thermom
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larger range w/o bursting.
not dangerous when it breaks, mechanical readings more consistent then eye spotting. |
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eletrolytic cell
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external power source with nonspontaneous rxn
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voltaic cell
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eletrochemical cell with spontaneous rxn
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lead acid battery
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lead oxide and lead and then use electrolyte (sulf acid) to produce e- then conect to battery charge put on obj of desire
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nerst eqn
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Ecell=E (naught cell) - (.0592/n)logQ
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relationship between E naught cell and K
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K=10^(nE(naught)/ .0592)
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chemical kinetics
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the study of the factors that control the rxn rates
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major factors that determine the rate of chem rxns
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1)temp
2) conentration 3)catalysts 4) rate of reactants diffusion and mixing |
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mechanism
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all of the elementary steps that take place in rxn
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determine Ea expirementaly
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carry out rxn at dif temps and measure rate at each temp then graph 1/T and the slope will be -Ea/2.3 R R=8.31
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color changes at cathode and anode
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cath: changed yellow
An: phenothalien changed pink |
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dillution has what effect on buffer capactiy
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decreases it as concentration is reduced
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dilliutions effect on the pH of a buffer
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none, the ratio of concentrations stays the same.
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Henderson hasselbalch eq
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Ph= Pka+log (In-/Hin)
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