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Chemistry F3341
Question | Answer |
---|---|
ACIDS | Proton Donors - tranfers H+ ions to something else |
CHROMATOGRAPHY | 1. Sample on filter paper, 2. placed in solvent (solvent doesn't touch line), 3. sealed until risen to solvent front, 4. use ninhydrin to see spots |
RATE-DETERMINING STEP | Slowest reaction, needed first before reaction can continue, includes everything in rate equation |
PRECIPITATION COLOURS OF: Fe(+2), Fe(+3), Cu(+2), Co(+2) | Fe(+2) = Green Fe(+3) = Brown Cu(+2) = Blue Co(+2) = Pink |
LIGANDS | An electron pair donor to a metal ion |
INTERMOLECULAR BONDS IN PROTEINS | ID-ID = between non-polar side chains, centres of proteins contain these so does not interfere with hydrogen bonding Hydrogen Bonding = form between amide links in secondary structures Ionic bonding = between ionisable side chains |
PROTEIN STRUCTURES | Primary - Order of amino acids joined together Secondary - arrangements of protein chains (helix or sheet) Tertiary - overall shape of protein (chains folding up further) |
PROTEIN | Condensation reaction with two amino acids (protein + water) |
AMINO ACIDS | one amino group and one carboxylic group |
ACIDIC NATURE OF PHENOLS | Reacts with hydroxide to form salts Doesn't react with carbonate |
TEST FOR PHENOL | Using neutral iron(III) Chloride Yellow ---> Purple |
BIODEGRADABLE/DEGRADABLE POLYMER | Biodegradable - breaks down completely into CO2 + H20 Degradable - breaks down into smaller fragments when exposed to light, heat or moisture |
CORROSION PREVENTION | Sacrificial metal Barrier protection e.g. oil, grease, paint, polymer coating |
SACRIFICIAL METAL | More electrode potential galvanising zinc blocks |
ZWITTERIONS | molecule contains both -ve and +ve groups neutralises effect of acid/alkali addition |
KETONE/ALDEHYDE REDUCTION | changes to alcohol use strong NaBH4 |
HALF CELLS | Standard Electrode Potential EMF of half cell compared to standard hydrogen half cell |
RECRYSTALLISATION | 1. Disoolve into a minimum amount of very hot solvent 2. Allowed to cool 3. Pure solid recrystallises first (impurities takes longer) 4. Filter to collect pure solid 5. Wash with ice cold solvent 6. Dry |
RATE OF REACTION CHANGE IN CONCENTRATION | Low concentration - 1st order (free active sites) High Concentration - Zero Order (no free active sites) |
COPOLYMERISATION | Adding Side groups into polymers chains Less packed, decreasing bonds between side chains |
CARBOXYLIC ACID | Primary alcohol oxidised to second stage |
KETONE | Secondary alcohol oxidised |
NUCLEOPHILLIC ADDITION OF CARBONYL COMPOUND AND HYDROGEN CYANIDE | Diagram |
CRYSTALLINE POLYMERS | Regular packing of chains due to regular structure of polymers Chains are closer together and intermolecular bonds have more effect = greater strength |
INCREASING STRENGTH IN POLYMER | Longer chains (critical length must be reached first) Increasing tensile strength -->long chains more tangled together --> long chains = more contact with other polymers |
ESTERS | An alcohol + carboxylic acid combined |
MASS SPECTROSCOPY | +ve ions can break apart into fragments Difference between molecule ions mass and mass of peak shows mass of fragment |
AMORPHOUS POLYMERS | Chains are far apart and tangled up with lots of freedom movement |
ACIDIC NATURE OF CARBOXYLIC ACID | Reacts with hydroxide to salts Reacts with carbonate produces fizzing of CO2 forms salts |
PRODUCING AMIDES | Carboxylic acid + amine --> amide + H20 -NH2 group reacts with -COOH group --> secondary amide group formed |
COLD-DRAWING | Pulling plastic to make it crystalline and have necked-region Neck will be more crystalline increases polymers strength |
INDUSTRIAL PREPARATION OF NYLON | Easier if acyl chloride is used instead of carboxylic acid HCl is eliminated instead of H2O |
OXIDATION OF ALCOHOLS | Acidified dichromate Heated under reflux |
ACYL CHLORIDE | -oyl chloride prefix COCl |
ALKALI | Base that dissolved in H20 producing Oh- |
PROPERTIES OF AMINES | Low Mr - gases/volatile liquids Most properties due to lone pair of electrons on N atom Very soluble in water, a base, a ligand, a nucleophile (similar to ammonia) Hydrogen bonding with H20 --> Amines with larger alkyl groups are less soluble |
PLATICISERS | Placed between chains letting chains slide - more flexible |
AMIDE | CONH2 |
REACTIONS ATOMS ECONOMY | Rearrangement/addition = 100% Substitution/Elimination = <100% Condensation = addition --> elimination |
CHROMATOGRAPHY | 1. Sample spotted on solid support material 2. Suitable solvent rises up 3. Series of spots seen (on for each compound in mixture) 4. If spots aren't coloured - need to be developed (amino acids/ninhydrin) |
BOND VIBRATIONS | Frequencry of absorption are different for each molecule because of strength of bonds Symmetric stretch Antisymmetric stretch Bending |
STRENGTH OF ACID DEPENDS ON? STRONGEST ACID? | Negative on O atom can move between C=O for more stability (delocalised) Carboxylic acid (pH 2/3) |
ACID ANHYDRIDE | two carbolic axid joined together by the O atom |
MAKING AN ESTER WITH ALCOHOL | Alcohol + carboxylic acid heated under reflux with concentrated sulphuric condensation |
MAKING AN ESTER WITH PHENOL | Phenol + acid anhydride/ acyl chloride Acid anhydride - heated under reflux Acyl chloride - reaction at room temperature No water present in both |
ISOTACTIC POLYMERS | All branches on one side --> better intermolecular force - closely packed |
HYDROLYSIS WITH AMIDES | Heated under reflux with: --> aqueous acid catalyst = product has ammonium ions CH3COOH + NH4+ --> aqueous alkali catalyst = carboxylate ions product Ch3COO- + -NH2 |
HYDROLYSIS OF ESTERS | Acid catalyst (H2SO4) --> equilibrium Alkali (NaOH) produces carboxylate salt --> goes to completion |
AMINES: NEUTRALISATION BY ACIDS | Amines with H30+ goes to completion producing amine ion + H20 --> Solution loses strong amine smell |
AMINES: ACYLATION TO FORM AMIDES | React with acyl chlorides in anhydrous condition --> reaction is very vigorous CH3COCl + NH3 --> CH3CONH2 + HCl |
CHAIN LENGTH OF POLYMERS | With longer chains there are more intermolecular bonds --> greater strength Flexibility depends on the ability of polymer chains to slide over each other |
pH | -log[H+] |
BASE | Proton acceptors Substance that accepts H+ ions |
WEAK ACID | Not fully dissociates Equilibrium to the left |
STRUCTURE OF POLYMERS | Mixtures of crystalline and amorphous regions |
ADDITION POLYMERISATIONS | Monomers with C=C bonds bond together to form a polymer |
CONDENSATION POLYMERISATION | Diamines + Dicarboxylic acid used polymer chains made --> monomer units linked together by amide groups individual steps are condensation reactions POLYAMIDES |
OPTICAL ISOMERISM | Two forms can't super impose on each other chiral - can't super impose on mirror images CORN RULE = COOH, R, NH2 clockwise = L-amino acid anti-clockwise = D-enantiomer |
DELOCALISATION | Electric charge getting spread out CH3CH20 - very unstable, charge located on O atom (pH 7) PHENOL - more stable, charge spread onto benzene ring (pH 5/6) COO- - even more stable, charge spread across -COO group (pH 3/4) |
STRONG ACID | Fully dissociates Equilibrium to the right |
MELTING TEMPERATURE (Tm) | Further heating, crystalline breaks down --> polymer becomes viscous fluid |
ALDEHYDE | -COH |
GLASS TRANSITION TEMPERATURE (Tg) | Heating up glassy material, polymers can move easier to each other --> becomes flexible with typical plastic properties |
ORDER OF REACTION | Zero order - concentration does nothing 1st order - rate doubles when concentration douables 2nd order - rate quadruples when concentration doubles Rate = K[A][B] |
AMINO ACID PAPER CHROMATOGRAPHY | To identify amino acids present in a peptide Hydrolysed under reflux - product compared to known samples of pure amino acids |
PROTEIN HYDROLYSIS | Heat under reflux with moderately concentrated acid/alkali |
INCREASING FLEXIBILITY OF POLYMERS | Tg value needs to be lowered --> copolymerising and plasticising copolymerise - adding side groups to chains (less packed, decreased bonds) Plasticiser - places between chains letting them slide |
POLYAMIDES | Amide groups linking monomers together -->aka nylon |
EXAMPLES OF LIGANDS | Water (no charge) Ammonia (no charge) Cyanide (-1) Chloride (-1) Hydroxide (-1) |
ELECTRON CONFIGURATION OF Cu AND Cr | Cr - 1 1 1 1 1 1 Cu - 1 1L1L1L1L1L |
CIS/TRANS | Trans - E (across from each other) Cis - Z (On same side) |
OXONIUM ION | Occurs in every acidix solution Properties of acidic solutions are all properties of H3O+ |
AMINES | R-NH2 |
BIDENTATE LIGANDS | Ligand can donate two lone pairs of electrons to central metal ion to form two coordinate bonds |