Paper 2-2020 Flashcards
Overall rate of reaction definition
Sum of powers /indices(which conc. are raised to.)
Explain how structural feature of enzyme enable it to catalyse the hydrolysis of isomer g and not F?
Enzyme has an active site
G enantiomer has the correct stereochemistry / complementary shape)
Alcohol warmed with acidified k2cr2o72-. Give obs.
Orange Sol turns green
Way to detect if ethanoic acid reacts with alcohol
Sweet smelling liquid
Reason why mixture is poured into Na2CO32-
To reedit with acid (remove xs acid)/neautralise
How infra red spectra to distinguish between two similar isomers?
Unique fingerprint region. Compare fingerprint region to database/known spectra
Suitable apparatus to measure out acid anhydride
Measuring cylinder/ 10cm3 pipette
Hazard of using H3PO4
Corrosive
Difference in mp of crude aspirin to mp of pure
Value is lower
Crude will have mp if range of values
Two precautions when heating mixture of ethanol and crude aspirin
Hear to temp below bp so ethanol doesn’t boil away
Use water bath no Bunsen as ethanol = flammable
Why is small amount of cold ethanol added to Büchner funnel when filtering pure aspirin?
To avoid aspirin dissolving/ remove any soluble impurities.
Use of species formed between large excess of 2 brompropane and ammonia
Cationic surfactant/ hair conditioner
Repeating unit of polystyrene
[-C-C-] with H and one benzene on top of a C
Why Si(CH3)4, CCl4 and CDCl3 used in H 1Nmr
CDCl3 or CCl4= solvent. TMS as reference/ calibration. It is inert
Both have no H atoms to give any signals for CDCl3 and CCl4.
CCl4= non polar therefore good solvent for non polar organic molecules.
CDCL3= polar covalent molecule therefore good solvent for polar organic compounds
TMS as reference:
Lots of H give one signal/environment. Easy to remove/volatile/low bp
Why it is difficult to predict chemical shift for peak
H attached to both C-Cl and adjacent to C=O so doesn’t fit with data in table B
Why reaction is slower than other reaction?
C in C=O is less delta positive as CH3 attatched us electron donating/ had +ve inductive effect therefore higher EA.
