Paper 2-2018 Flashcards
How can a single radical cause decomposition of many molecules of ozone?
Cl radical is regenerated- causes chain reaction in decomposition of ozone
Iupac name for CH2(OH)CH(CH3)CH2Br
3- bromo-2-methylpropan-1-ol
Why halogenoalkanes attacked by nucleophiles
Halogen is more electronegative than carbon
C is partially positive/e- deficient
Lp on Nucleophilicity donated to partially positive carbon
Displayed formula for compound- C4H6O2 infrared range 1680-1750
CH3
O\CH-CH-CH\O
Compound has empirical C3H4NO and reagent
CN-CHOH-CH3H-CHOH-CN
KCN and dil.acid
Why distillation allows propanol to be separated by other organic compounds in reaction mixture?
Alcohol- 97°
Propanol- 49°
Propanoic-141°
Alcohol and propanoic acid have H bonding
Aldehyde has dipole dipole forces
Forces in aldehyde are weaker therefore evaporates first
Ways to maximise yield obtained via distillation
-Keep temp if reaction mixture below its bp
-Cool distillate
Confirm sample of aldehyde doesn’t have carboxylic acid
Add Na2CO3(carbonate) or Mg
Effervescence pr bubbles confirm presence of acid
Mechanism when 2°alcohol dehydrated in presence of H2SO4 and forms alkene
Elimination
Less polar stereoisomer and how it arises
E-Pent-2-ene
Rotates and each C has 2 diff groups attatched
Kc with tot. Vol.
Products /reactants
Divide each by vol if in cm3 divide by 1000
Gradients of rate equation
Gradient=-Ea/R
Adding water to eq mixture will lower conc of A
Decreases conc of A. Eq. shifts to side with more pimples to oppose decrease in conc
Bonding in and shape of benzene and stability
Bonding- Each c has 3 covalent bonds, spare e in p orbital overlap to form pi cloud, delocalisation
Shape- planar, hexagon, 120°, c-c bonds equal in length
Stability/ expected of cyclohexatriene- -360 (-120x3) , hydrog of benzene is less exothermic by 152, benzene lower in energy more stable
Estimate value for hydrog of cyclohexa-1,3, diene
Between -239 and 121
Double bonds sepetste by single bond/ alternating
Allows some delocalisation/ overlap of p orbitals
CH3CH2COCl with AlCl3
Electrophylic sub reaction
CH3CH2COCl+AlCl3—> CH3CH2-O+ + AlCl4-
Alcohol reacts with ethanol chloride
Ester formed
Obs- misty steamy fumes
Mech- nuc.add.elim
How do H bonds form on polypeptide chains
Partially positive H/ electron deficient H on N-H attracted to lp on Oxygen
Bond between two polypeptide chains and protein structure
Sulfur bonds
3°
Zwitterion of dipepitide by alanine and serine
And H and + on LHS of A and remove H and make negative charge on RHS attached to S. remove H on NH2 and H making negative charge on COOH
Complimentary bases
A+T- 2 H bonds
C+G- 3 h bonds
Better to prep 1° amines from nitriles rather than from halogenoalkanes
With Halo- further reactions occur/impure product formed/ lower atom economy
With nitriles- no further reaction/single product/ higher atom econ
When propylamine dissolved in water
Forms OH- and NH3+ on compound
Turns blue
