UPMSP Intermediate Chemistry flashcards
UPMSP Intermediate Chemistry · Build recall with a focused review session.
35 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Raoult's law
- The partial vapour pressure of each volatile component of an ideal solution equals its mole fraction in the liquid multiplied by the vapour pressure of the pure component at the same temperature.
- van 't Hoff factor
- The ratio of the observed colligative property to the value calculated assuming no dissociation or association. It is greater than one for electrolytes such as NaCl and less than one for associating solutes.
- Azeotrope
- A liquid mixture that boils at constant composition and temperature, so its vapour has the same composition as the liquid. Such mixtures cannot be separated by ordinary fractional distillation.
- Osmotic pressure
- The excess pressure that must be applied to a solution to just prevent solvent passing through a semipermeable membrane. It equals CRT for dilute solutions and is used to find macromolecular masses.
- Nernst equation
- An equation relating cell potential to standard potential and reaction quotient: E = E° − (0.0591/n)·log Q at 298 K. It predicts how concentration changes shift electrode potentials.
- Kohlrausch's law
- At infinite dilution, the molar conductivity of an electrolyte equals the sum of the limiting molar conductivities of its individual ions, each multiplied by its stoichiometric coefficient.
- First-order reaction half-life
- The time for the reactant concentration to fall to half its initial value. For a first-order reaction it equals 0.693/k and is independent of the starting concentration.
- Activation energy
- The minimum extra energy that colliding reactant molecules must possess for a reaction to occur. It appears in the Arrhenius equation and is lowered by a catalyst.
- Pseudo-first-order reaction
- A reaction that is second order overall but appears first order because one reactant, usually the solvent or water, is present in such large excess that its concentration stays essentially constant.
- Lanthanoid contraction
- The steady decrease in atomic and ionic radius across the lanthanoids caused by poor shielding of nuclear charge by 4f electrons, making Zr and Hf almost identical in size.
- Crystal field splitting
- The energy gap between the lower and higher d-orbital sets when ligands approach a metal ion. Octahedral splitting is larger than tetrahedral splitting for the same ligands.
- Geometrical isomerism
- Isomerism in which ligands occupy different spatial positions relative to each other, giving cis and trans forms in square planar or octahedral complexes of suitable formula.
- SN1 mechanism
- A two-step nucleophilic substitution in which the leaving group departs first to form a carbocation, then the nucleophile attacks. Rate depends only on the substrate and stereochemistry is largely racemised.
- SN2 mechanism
- A single-step nucleophilic substitution in which the nucleophile attacks the carbon from the side opposite the leaving group. The rate depends on both reactants and the product has inverted configuration.
- Finkelstein reaction
- The conversion of an alkyl chloride or bromide to the alkyl iodide by heating with sodium iodide in dry acetone, where the precipitated sodium halide drives the equilibrium forward.
- Lucas test
- A test using anhydrous zinc chloride in concentrated hydrochloric acid that distinguishes alcohols by how quickly turbidity appears: tertiary immediately, secondary in minutes, primary only on heating.
- Williamson ether synthesis
- The reaction of a sodium alkoxide with a primary alkyl halide to give an ether. Tertiary halides give elimination products instead of the ether.
- Reimer–Tiemann reaction
- The treatment of phenol with chloroform and aqueous sodium hydroxide followed by acidification, which introduces a formyl group mainly at the ortho position to give salicylaldehyde.
- Tollens' test
- A test in which an aldehyde reduces ammoniacal silver nitrate to metallic silver, forming a mirror on the tube. Ketones give no such reaction.
- Iodoform test
- A test in which a compound containing a CH₃CO group or a CH₃CH(OH) group gives a yellow precipitate of triiodomethane with iodine and sodium hydroxide.
- Cannizzaro reaction
- A disproportionation of aldehydes lacking alpha hydrogen atoms, such as methanal or benzaldehyde, in strong alkali, giving the corresponding alcohol and carboxylate salt.
- Hinsberg test
- A test using benzenesulfonyl chloride in alkali that distinguishes amines: primary amines give a soluble sulfonamide, secondary an insoluble one, and tertiary amines do not react.
- Peptide bond
- The amide linkage formed between the carboxyl group of one amino acid and the amino group of another with the elimination of a water molecule, joining them into a protein chain.
- Denaturation of proteins
- Loss of the secondary and tertiary structure of a protein by heat, pH change, or chemicals, without breaking peptide bonds, so the primary sequence remains intact.
- Condensation polymerisation
- A stepwise polymerisation in which monomers with two functional groups join with the elimination of a small molecule such as water, giving polyamides, polyesters, or phenol-formaldehyde resins.
- Packing efficiency
- The fraction of unit-cell volume occupied by atoms. It is 52.4 percent for simple cubic, 68 percent for body-centred cubic, and 74 percent for face-centred cubic.
- Schottky defect
- A point defect in ionic crystals in which equal numbers of cations and anions are missing from their lattice sites, so the density of the crystal decreases.
- Freundlich isotherm
- An empirical relation for adsorption from solution or gas: x/m = k·p^(1/n), where x/m is the amount adsorbed per gram of adsorbent and 1/n lies between zero and one.
- Interhalogen compounds
- Compounds formed between two different halogens, such as ClF₃ or BrF₅, in which the larger halogen is central and the geometry depends on the number of lone pairs.
- Ellingham diagram
- A plot of the standard free energy of formation of metal oxides against temperature. The metal with the more negative curve can reduce the oxide of a metal above it.
- Froth flotation
- A concentration method for sulfide ores in which powdered ore is agitated with water, oil, and a frother so that sulfide particles attach to bubbles and float while gangue settles.
- Markovnikov's rule
- When a hydrogen halide adds to an unsymmetrical alkene, the hydrogen atom attaches to the carbon bearing more hydrogen atoms, giving the more stable carbocation intermediate.
- Aromaticity criteria
- A cyclic, planar, fully conjugated system with (4n + 2) pi electrons is aromatic. Systems with 4n pi electrons in the same geometry are antiaromatic.
- Chromyl chloride test
- A test for chloride in which the salt heated with potassium dichromate and concentrated sulfuric acid gives red vapours that turn sodium hydroxide solution yellow.
- Lassaigne's test
- A sodium fusion test in which organic nitrogen, sulfur, and halogens are converted to sodium cyanide, sodium sulfide, and sodium halides, then detected by specific colour reactions.