Scholastic Bowl Science Experimental Processes

Water Desalination

**The CETO project uses wave power technology in order to achieve this process.**

Water Desalination

**The MVC form of this process uses a flow compressor to move liquid across a thermal gradient in a vacuum chamber.**

Water Desalination

**One form of this process uses an activated carbon filter which prevents damage to the TFC membrane and was invented by Loeb and Sourirajan.**

Water Desalination

**Methods for performing this process include multi-stage flash (*)** distillation and electrodialysis.

Water desalination

A widely used form of this process applies pressure through a semipermeable membrane and can be impeded by the formation of biofilms. That process is reverse osmosis.

Vacuum

**One technique often performed in this state uses a Buchner funnel to extract a dissolved solid from a solvent.**

Vacuum

**Another technique performed in this state uses a spin bar instead of boiling chips, because that variant does not need to heat the liquid.**

Vacuum

**Water-traps and water aspirators are occasionally used in both the aforementioned namesake filtration and distillation techniques.**

Vacuum

**Experiments carried out in this state usually require Pyrex or round-bottomed glassware because Erlenmeyer flasks or those with (*)** cracks may spontaneously collapse.

Vacuum

The two walls of a Dewar flask are separated by material in this state, which is often achieved by means of a pump.

Distillation

In the bulb-to-bulb form of this process, an apparatus known as a kugelrohr is used.

Distillation

Before performing one type of this process, a McCabe–Thiele diagram may be drawn.

Distillation

The minimum number of equilibrium stages needed for another type of this process can be determined with the Fenske equation.

Distillation

Pieces of glass tubing known as Raschig rings are used in a Hempel column in a type of this process, which also may utilize a Vigreux column.

One variant of this laboratory technique used for compounds unstable at high temperatures uses a Kugelrohr apparatus, while another variant uses a Perkin Triangle. Those types are the “short path” and “vacuum” types.

Fractional Distillation

**This process can be modeled using a diagram that includes operating lines for stripping and rectification sections; the latter line has slope of R over R plus one, where R is the reflux ratio.**

Fractional Distillation

**That modeling method is named after McCabe and Thiele and gives the theoretical number of stages required to achieve the desired result.**

Fractional Distillation

**This process requires that a namesake type of (*)** column, which is packed with a nonreactive substance such as glass beads, be placed before the Y-adapter.

Fractional Distillation

This allows for the formation of a vapor-liquid equilibrium so that only the most volatile vapors rise to the top and are allowed into the condensing tube.

Distillation

**The Perkin triangle, which is now typically not triangular, is used to perform this procedure in an inert atmosphere.**

Distillation

**It is not chromatography, but efficiency is improved in this procedure with an increasing number of theoretical plates.**

Distillation

**An apparatus that allows this technique to be applied to air-sensitive substances uses three Teflon taps and is called the Perkin Triangle.**

Distillation

**One variant of this technique uses a Vigreaux column, which separates the mixture into several trays with different temperatures.**

Distillation

**A cold finger or a jacket condenser can be used in one arm of this technique’s apparatus, and this technique commonly employs reflux to increase yield.**

Distillation

**The classic method to generate pure oxygen and nitrogen is to do this process to air at cryogenic temperature.**

Distillation

**The outlet streams of this process are called the bottoms and overhead.**

Distillation

**During this process, the rectifying and stripping sections intersect at the feed.**

Distillation

**Three-neck round-bottom flasks are attached to packed columns for this process in the lab.**

Distillation

**The number of degrees of freedom for this process is equal to 2N plus C plus 9 for a multicomponent system.**

Distillation

**Pinch points are intersections between the equilibrium and operating lines in this technique, which are graphed on a McCabe-Thiele [“meh-cayb-thee-luh”] plot.**

Distillation

**Substances in this technique are categorized into “light key” or “heavy key” components, the mole fractions of which are used in the Fenske equation to calculate the number of theoretical plates necessary.**

Distillation

**The feasibility of this technique can be determined from a residue curve.**

Distillation

**Using a molecular sieve or an entrainer allows this process to be conducted on an azeotrope, which deviates from (*)** Raoult’s law.

Raoult’s Law

**This law can be derived by solving for the fugacities of a system’s components, and it can be used to calculate the dew-point and bubble-point pressures used in a P-x-y diagram.**

Raoult’s Law

**Solutions with strong cohesive forces, such as a mixture of ethanol and acetone, can exhibit a positive (*)** deviation from this law, and such deviations, called azeotropes, cannot be separated with fractional distillation.

Distillation

**The “destructive” form of this technique is often applied to coal and occurs through a pyrolysis reaction.**

Distillation

**The optimal number of equilibrium stages in this technique, called theoretical plates, can be determined using the McCabe-Thiele method.**

Water Purification

**One procedure to perform this task uses a polymer of m-phenylene [[“fen-ill-ene”]] diamine and trimesoyl chloride; that procedure also uses a cellulose triacetate membrane.**

Water Purification

**Another procedure used to perform this task uses heat exchangers and is called multi-stage flash.**

Water Purification

**The substance that has undergone this process can be labelled Milli-Q, dd, or (*)** DI.

Chromatography

**The output of this technique provides the more common name for glycated hemoglobin, or hemoglobin A1c.**

Chromatography

**A solvent delivery system is used in a form of this technique which runs in isocratic or gradient modes depending on the composition of its solvent, and is regularly run in tandem with mass spectrometry in proteinomics.**

Chromatography

**Several washes of imidazole may be used in a form of this technique used to (*)** isolate proteins designed to contain poly-his tags.

Chromatography

This technique's output is often separated into fractions of the eluent which may be analyzed separately. In this technique, a mobile phase carries mixtures of interest past a stationary phase.

Chromatography

**One version of this procedure commonly uses dextran blue to measure the void volume.**

Chromatography

**Automated fraction collectors are used with several types of this procedure.**

Chromatography

**In one form of this procedure, proteins with a poly-histidine tag bind to metal ions.**

Chromatography

**Sephadex is used in the size-exclusion variant of this procedure.**

Chromatography

**One form of this process pumps the mixture with high pressure and is known as its (*)** “high-performance liquid” form.

Chromatography

The eluent in the “column” form of this process is chosen to have a retention factor of 0.2 to 0.3.

Chromatography

**Glutathione-binding GST is added onto proteins to perform a pull-down assay using this technique.**

Chromatography

**Proteins intended for one version of this procedure, which utilizes an imidazole buffer and nickel-NTA beads, are tagged with 6 histidine residues.**

Chromatography

**Cat·ion and an·ion exchange resins can be used in a type of this procedure run on (*)** columns.

Chromatography

One form of this technique traps small molecules in pores of an adsorbent material such as polystyrene.

Chromatography

**In another form of this technique, a sample passes through a flame ionization detector after passing through a “carrier gas” such as helium.**

Chromatography

**One form of this technique pumps a sample through a column filled with an adsorbent material using a solvent at a very high pressure.**

Chromatography

**A form of this technique in which molecules are filtered through a gel is commonly used to determine polymer dispersity and is called the “size-exclusion” form of this technique.**

Titration

**Permanganometry can use the redox variety of this technique to detect the concentration of iron II in a solution.**

Titration

**A form of this technique involves the oxidation of sulfur dioxide with iodine, and disodium EDTA is commonly used to carry out its complexometric variety.**

Titration

**Compounds like (*)** bromothymol blue and phenolphthalein are useful in determining the endpoint of this technique.

Titration

**A form of this technique is used to characterize heterogeneous systems by identifying their isoelectric point.**

Titration

**Another form of this technique relies on the chelation of EDTA to a metallic cation to form an octahedral complex.**

Titration

**One type of this technique uses the reduction of potassium permanganate from a +7 to +2 oxidation state to identify the end of this procedure.**

Titration

**The Kjeldahl (“KELL-tall”) digestion uses this technique after the sample is heated to determine a property of ammonia, and in the Winkler test, a thiosulfate solution is used to perform this technique.**

Titration

**Karl Fischer names a form of this technique used to determine the amount of water in a sample.**

Titration

**Colloids and emulsions have the (*)** zeta potential form of this technique performed on them to find the isoelectric point.

Titration

**An isothermal type of calorimetry which employs this process can be used to study the binding of small molecules to macromolecules like DNA and proteins.**

Titration

**Magnesium and calcium ions are chelated [key-lated] by EDTA in the complexometric type of this procedure.**

Titration

**Dichromates and potassium permanganate are used in the (*)** redox type of this technique.

Titration

Using polyprotic acids in this process yields multiple equivalence points. In this technique, which makes use of indicators like phenolphthalein, a buret slowly drips a solution into an analyte to yield a color change.

Calorimetry

**One form of this technique uses a parameter equal to n times K-sub-a times M known as the c-value.**

Calorimetry

**That technique is used to monitor biomolecular binding events.**

Calorimetry

**Another form of this technique examines peaks to find the glass transition temperature.**

Calorimetry

**One form of this technique consists of two cells in an adiabatic jacket and is its (*)** "isothermal titration" variety.

Calorimetry

One type of this technique used for combustion reactions operates under constant volume to eliminate PV work.

Calorimetry

**One form of this technique uses an adiabatic jacket to measure the binding affinity between ligands and macromolecules.**

Calorimetry

**Another form of this technique linearly increases temperature to measure a polymer’s glass transition temperature.**

Calorimetry

**One form of this technique uses an isochoric container full of pure oxygen to measure properties of a fuel upon (*)** combustion.

Calorimetry

**The change in enthalpy is proportional to the area under the curve in the “differential scanning” type of this technique, which detects phase changes.**

Calorimetry

**A thermometer is immersed in the water around a metal combustion chamber in the constant-volume (*)** “bomb” type of this technique.

Calorimetry

**In one form of this technique, a sample is placed in a pan sitting on a constantan disc with a chromel wafer underneath.**

Calorimetry

**Another form of this technique can use background experiments such as “water into water” and displays its results in a graph where spikes correspond to ligand injection.**

Calorimetry

**In one form of this technique, a thermocouple measures the temperature difference between a sample and reference pan. That form can be used to calculate the glass transition temperature and is its “differential scanning” variant. A historical version of this technique uses the latent heat of fusion of ice to calculate the change in energy of a sample.**

Calorimetry

**An application of this technique to directly measure “gross energy” has largely been superseded by the purely arithmetic Atwater system.**

Mass spectrometry

**An ionization process like MALDI or ESI is used to prepare samples undergoing this technique, and basic versions of these devices use perpendicular electric and magnetic fields to select particles by their (*)** velocity.

spectroscopy

**Gold or silver surface plasmons are central to a “surface-enhanced” variant of this technique, another form of which is often paired with gas chromatography.**

spectroscopy

**Symmetric molecules are (*)** “inactive” in one form of this technique, and Beer’s law is used to measure absorbance in another.

mass spectrometry

Some forms of this technique use a Penning trap, which forces the ions to rotate at the cyclotron frequency, which is named for a device that uses two D’s and a magnetic field to rotate charged particles in circular tracks. 

centrifugation

**It’s not a form of chromatography, but this technique has preparative and analytical types.**

centrifugation

**The quantities resulting from this technique are non-additive and defined in units of time, but they’re more frequently expressed in (*)** svedbergs.

centrifugation

This technique eventually results in a pellet and a supernatant, and a common example of its use is isolating plasma from the other components of blood.

centrifuge

The use of these devices is sometimes described by the adjective “isopycnic” \[“ice-oh-picnic”\], which originally referred to surfaces of constant density inside a fluid.

centrifuge

One of these devices is used to find the packed cell volume of blood.

centrifuge

The Zippe \[ZIP-uh\] type of these devices is sometimes regulated by international treaties because it is used to enrich uranium.

centrifuge

The basket type of these devices is used to process cane sugar and is good at separating liquids from solids.

centrifugation

**The run-time of this procedure is measured by k, the clearing factor.**

centrifugation

**Cesium chloride is used in the isopycnic form of this procedure, enabling identification of the AT to GC base pair ratio.**

centrifugation

**Ribosomal subunits are distinguished based on their values for a parameter in this technique measured in (*)** Svedberg units.

centrifugation

**The applied strength of this technique is measured in RCFs, and tabletop versions of these instruments usually have a "Fast Temp" option.**

centrifugation

**Polyribosome binding to mRNA is commonly measured using the isopycnic version of this technique.**