The Letter "F" in Chemistry
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- Fat - A triester of glycerol that is found as a solid at room temperature.
- Fatty Acid - A long carboxylic acid chain.
- Favorskii Reaction - A reaction between a hydroxide ion and an alpha - haloketone resulting in the formation of carboxylic acids and their derivatives.
- Feedback Inhibitor - A control mechanism in biosynthetic pathways in which an enzyme that is involved in the formation of a particular compound in the cell is inhibited when that compound accumulates to a certain concentration; serving to balance the amount produced by the amount present.
- Fingerprint Region - The area on the right - hand side of an IR spectrum containing absorption bands that are characteristic to the compound. These absorptions are due to various types of bending vibrations within the molecule.
- First Law of Thermodynamics - This law states that energy cannot be created or destroyed; therefore, the energy of the universe is constant.
- First - Order Rate Law - A reaction in which the rate is proportional to the concentration of one reactant. An example of a first - order reaction is one in which the rate determining step is a decay process.
- Fischer - Esterification Reaction - The reaction in which a carboxylic acid and an alcohol react, in the presence of an acid catalyst (such as H2SO4), to form an ester.
- Fischer Projection - A method for representing the spatial arrangement of groups bonded to an asymmetric carbon. This method uses the point of intersection of two perpendicular lines to represent the asymmetric center. Groups located along the horizontal axis project out of the page and groups located along the vertical axis point away from the viewer.
- Fission - In terms of nuclear chemistry, the process in which a heavier nucleus is split into lighter nuclei.
- Flagpole Hydrogens - The two hydrogen atoms in the cyclohexane boat conformation that are closest to each other.
- Formal Charge - A value that is determined by using the equation: (number of valence electrons) - (number of bonds + number of nonbonding electrons) This value can be particularly useful in determining the best Lewis structure for a given compound and for helping to determine possible reactivities of the atoms in a compound.
- Formula Equation - A reaction equation that represents the the reactants and products in solution in their undissociated forms whether they are weak or strong electrolytes.
- Fossil Fuel - Coal, natural gas or petroleum. These are all carbon - based molecules derived from the decomposition of once - living organisms.
- Free Radical - A species that contains an unpaired electron.
- Freezing Point Depression - The decrease in freezing point of the solvent in a solution. This drop in freezing point is due to the solute's disruption of the normal intermolecular forces in the solvent.
- Frequency - The number of waves (or cycles) that pass through a given point in space per second.
- Friedel - Crafts Acylation - An electrophilic substitution reaction that puts an acyl group on a benzene ring. This results in the formation of a deactivated product that does not undergo a second addition.
- Friedel - Crafts Alkylation - A Lewis acid catalyzed electrophilic substitution reaction that puts an alkyl group on a benzene ring.
- Frontier Orbitals - The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).
- Frontier Orbital Theory - A theory that is used to explain the relationships among reactant, product and reaction conditionsin a pericyclic reaction.
- Functional Group - A center of reactivity in a molecule.
- Functional Group Interconversion - The conversion of one functional group into another functional group.
- Functional Group Region - The left-hand two-thirds of an IR spectrum where most functional groups show absorption bands.
- Furanose - A carbohydrate containing a five-membered-ring
- Furanoside - A glycoside that contains a five-membered-ring
- Fused Bicyclic Compound - A bicyclic compound in which the rings share two adjacent carbons.
- Fusion - The process of combining two nuclei to produce a heavier, more stable, nucleus.