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75 Cards in this Set
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- Back
Absorption |
The drawong up of a liquid through a mass; permeating the bulk of the absorbing material |
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Acidic |
Having a ph less than seven litmus paper pink |
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Adsorption |
Special kind absorption restrocted to adhesion of material to the surface of the bodies. Attached either by chem bonds or vander whal forces |
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Alkaline or basic |
Ph greater than seven litmus paper blue |
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Anhydrous |
With out water all water has been removed from substance so if comes in contact with water it will absorb quite readily |
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Aqueous phase |
Liquid layer in which water is the solvent (density = ~1g/ml) |
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Azeotrope |
Mixture of 2 or more substances that distills at constant temp and w constant composition even tho seperately components have diff bps. Usually occurs when intermol interactions like h bonding take place |
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Benchtop extraction |
Process of recovering a desired substance that has been accidentally spilled on Benchtop by scraping up substance and then purifying by recrystallization or soaking up a solid or liquid substance with cotton that has been saturated with suitable solvent and then extracting from cotton with more solvent. |
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Boiling chip |
Granules of porous alundum which release bubbles of entrapped air to a soln as it is being heated. These bubbles provide a path by which the vapour of boiling liquid can be smoothly led to surface and released. Can never be used twice and never be added to hot soln near bp since violent frothing will result. |
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Boiling point |
Temp at which vapour pressure of liquid is equal to atmospheric pressure. Bp is constant for pure substance. |
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Bumping |
The sudden violent surge of vapour breaking from surface of a liquid. If liquid is free of trapped air pockets bubbles do not form readily and temp of liquid may rise above boiling.point. liquid becomes super heated and when a bubble does form its internal pressure rapidly exceeds external pressure and bumping occurs.can be prevented w boiling chips and by stirring. |
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Capillary action |
Phenomenom of elevation or depression and of adhesion and cohesion of a liquid observed in a thin tube which is placed in a liquid due to surface tension |
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Carcinogenic |
Cancer causing agent which could cause death or permanent damage as a result of repeated of exposure over a long period of time. |
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Catalysis |
The acceleration or promotion of a chem rxn by a reagent or catalyst which itself remains unchanged. |
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Celite |
White coarse powder made up of diatomaceous earth also known as filteraid. Used during filtration to prevent small particles from passing thru filter paper. |
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Condensate |
Liquid that results when a gas is cooled. |
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Condensation |
The process by which matter changes from gaseous to a liquid state |
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Condenser |
Apparatus in which gases are cooled until they become liquid. Direction of water flow is always against gravity. |
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Corrosive |
Having the ability to cause immediate damage upon contact. |
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Distillation |
Two part process on which 1. liquid is boiled thereby converting it to vapour and 2. the vapour is then recondensed to a liquid and collected in a diff container from original one |
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Distillate |
The condensed liquid obtained from distillation |
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Drying agent |
An inorganic salt that can form hydrates used to.remove small.amounts of water that have been absorbed by organic solvents. |
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Emulsion |
A finely dispersed suspension of one liquid layer in another which happens when dissolved materials in these liquids cause the mutual solubility of the two.layers to increase.often appaears as a foamy layer between two normally immiscible liquids. |
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Extraction |
Process of removing a desired substance from a soln or solid mixture based on diff in solubility. |
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Filtrate |
The liquid which passes thru a filter |
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Flammable |
Having the ability to burn |
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Fractionating column |
Glass tube having a large internal surface area upon which a gas can condense and evaporate many times before reaching the end of the column. |
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Hygroscopic hydroscopic? |
Attracts water |
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Ice bath |
A mixture of ice and water with a higher % of water. Much more effecient than cooling than ice byself (increases surface area) |
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Immiscible |
Substances unable to be blended; usually liquids like oil and water. Diff densities (seperate) |
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Inflammable |
Easily set on fire. |
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Labeling |
The following info where applicable should be included on official label of a sample that has been prepared : exp name section locker number, date of preparation, name and structure of compound, weight or yield in g (and % yield), any physical constants that were measured (not literature value) |
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Limiting reagent |
The reagent which is present in lowest amount according to stoichiometeric relationship of the rxn. |
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Melting.point. |
Temp at which solid and liquid phases of substance are in.equilibrium under external pressure of one atmosphere. Melting point usually consists of two temps. 1st is at which 1st drop.of liquid appears amongst crystals 2nd is at which whole mass is liquid. Purer compound the narrower the mp range. Unpure compounds=depressed and widened range. |
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Miscible |
Liquids capable of being mixed in all.proportions to form homogenous substances |
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Mol percent |
The number of.mols of substance in question divided by total number of mols of.all substances in the mixture. |
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Mother liqour |
The soln that remains after a crystallization. Consists of recrystallization solvent saturated with dissolved solute. |
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Mull |
Mixture of finally ground solid sample in an inert carrier liquid such as nujol. This is one method used to.prepare a solid sample to.allow you to.take an infared spectrum on.it. |
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Norit |
Activated charcoal which can be used to absorb small.amounts of.coloured soluble impurities from a soln. |
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Organic phase |
The liquid layer in which organic liquid is solvent ie ether. |
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Oxidation |
The chem rxn of oxygen or oxidizing agent with free elements and with compounds. This may result in 1. An increase in number of O molecules within a compound 2. An decrease in number of H molecules or 3. The loss of e- to an oxidizing agent. An oxidizing agent is reduced in oxidation. |
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Percentage recovery |
Final weight divided by initial weight times 100 . often used during recrystallization to determine how much was lost. |
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Percentage yield |
Actual yield divided by theoretical yield times 100. |
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pH |
Log [h3o+] a measure of the concentration of h ions in soln. Lless than seven is acidic. Greater than seven is basic. |
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Purification |
The process of removing impurities from a desired substance. Can be accomplished by such processes as recrystallization extraction and distillation. |
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Quantitative transfer |
The transfer of a substance from.one container to another so that none of substance is left behind in original container. Usually axcomplished by rinsing 1st container several times with suitable solvent and adding all rinses to 2nd container. |
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Recrystallize |
Purifying of a solid substance by dissolving material in.min amount of hot solvent and then allowing soln to cool slowly. As soln cools solubility of substances in solvent decreases and thus crystals fall out of soln. |
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Reduction |
Opp of oxidation. Chem rxn bt reducing agent and free elemnts or compounds. May result in 1. Decrease in O in compound 2. Imcrease in number of h 3. A gain of e- to compound supplied by reducing agent. Reducing agent is oxidized during reduction. |
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Reflux |
Process whereby heated liquid evaporates enters a condenser where it is allowed to cool to.liquid state and then flow.back to.original boiling soln. Good reflux is 1 drop/sec off end of condenser. |
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Refractive index |
The ratio.of sin of angle of incidence to the sin of angle of refraction; Measure of.retracting quality of a medium. The ratio of velocity of light in air to the velocity of light in another medium. This meaurement is dependent upon temp and the wavelength of light. Since they are temp dependent. Conversion is t1= t obs + (0.00045)(tobs-t1) |
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Residue |
That which remains left behind. The remainder. Usually the solid that remains after filtration |
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Rf |
The distance traveled by a solute on tlc plate divided by the distance traveled by the solvent on the same plate. Not a physical constant for a solute since it varies with solvent used, thickness of plate, and even the relative amount of substance spotted. |
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Rheostat |
An adjustable resistance for regulating electric current. Here it is used to regulate the temp of the thermowells since they have no regulating device. |
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Saponification |
The making of soap. The alkaline hydrolysis of a fat. |
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Saturated |
1. An inorganic compound it indicates that there are no double or triple bonds or rings. 2.in a soln it indicates that under ordinary temp and pressure cond the max amount of solute has been dissolved. |
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Schlierien lines |
Streaks or wavy lines in a soln indicating regions of diff densities usually indicating something is dissolving. |
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Scratching |
Using roughened end of glass rod to pull a little of recrystallization solvent above the surface of a liquid while scratching the rod against the side of the container to give a rough area for the first crystal to form. |
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Seeding |
Placing a seed or pure crystal of a substance in a saturated soln of compound to start the growth of the crystal lattice. |
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Slurry |
A suspension of fine solid particles in a liquid. |
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Solubility |
The amount of a solute that will dissolve in a set volume of solvent at a given temp. This is a temp dependent variable. |
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Solute |
The dissolved substannce in a soln |
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Solvent |
A liquid capable of dissolving a substance. |
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Solvent pair |
2 or more miscible solvents which when added together form a mixture having the appropriate properties for recrystallization. One usually dissolves compound very well while other dissolves compound poorly or not at all. |
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Streaking |
Streaking of a substance along a tlc plate. Usually occurs if too much of the initial material is spotted on the plate or the material is very polar and thus more attracted to plate than developing solvent and consequently very difficult to move up the plate. Latter case can usually be minimized by the addition of a few drops of acidic acid..or some polar liquid to the developing solvent to increase its polarity. |
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Successive extractions |
Taking your total volume of extracting medium and splitting it into several portions and adding each portion to a seperatory funnel containing an immiscible solvent mixing and removing this portion of extracting medium before adding the next portion. This ensures getting the best possible separation of components in a mixture. |
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Successive washes |
A series of washes of either a solid or liquid sample in which each individual wash is removed from the system.before the next one is added. Washes remove undesirable products. |
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Tailing |
Same as streaking. |
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Theoretical yield |
Maximum weight of a substance that could be produced in a run based upon the amounts of starting material used. |
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Tlc thin layer chromatography |
Procedure used to analyze a mixture by separating out its constituents by means of selective adsorption from a soln onto an active surface of finely divided solids. This partitioning process is based upon differences in polarity. |
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Turbidity |
Cloudiness in a soln usually caused by immiscible compounds. |
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Unsaturated. |
Opp of saturated. Double triple bond or rings exist. Or a soln in which more solute can be dissolved. |
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Vaporization |
The process of changing to a gas from a liquid to a solid |
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Volatile |
Tending to evaporate under ordinary temp and pressure conditions. |
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Washing |
Removal of unwanted materials from desired materials by rinsing them with a suitable solvent. |
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Actual yield |
The weight of substance that has been produced. |