chemistry paper 2 Flashcards
what is the order of reaction
amount of ions colliding in the rate determining steps
phenol compared to bromine
-phenol dosent need a halogen carrier
-oxygen’s lone pair of electrons interacts with the benzene ring of delocalised electrons so electrophilic attack more likely
-Tri-substitution of phenol compared to mono for benzene
-Bromination of phenol requires bromine in
aqueous solution but benzene requires liquid bromine
-Bromination of phenol requires room temperature but benzene requires heating (under reflux) /
reflux
why can some molecules form XCl5 and some cant
if the number they are in has another orbital e.g on 3p has 3d however if on 2p does not have 2d
how do impurities affect heterogenous catalsyts
they adsorb onto the surface
take up active sites
reduce weakening of bonds
less likely to deadsorb
electrophile
wants electrons
so is postive
nucleophile
gives away electrons
so is negative
which alcohol reacts with iodine in the presence of an alkali to form a yellow solid
secondary with CH3CHOH group
comparing boiling temp with no hydrogen bonding
london forces
- stronger has more electrons
permanent dipoles
-stronger is more electronegative
london forces are more influential/ take more energy to overcome
what produces HCl with PCl5
alcohol
TMS
tetramethylsilane
refrance peak
number of optical isomers
no of chiral centres x 2
distinguish between keytone + aldehyde using 2-4dnph
formation of yellow/orange/red (crystalline) precipitate
(Filter then) recrystallisation of products
determination of melting temperature
comparison (and hence identification) from use of
database/known values
alkene to alcohol
steam and acid
first order reactions
half lives are equal
do other fc
why not opticaly active
intermediate / carbocation is (trigonal) planar around the
reaction site / C+ / central carbon
alkene to alkane
h2 + nickel catalyst
used to make margirine
how to work out number of ions
moles x number of ions
e.g (NH4)2SO4 = 3
x avragados consta
bonding in co
triple
why are amino acids solid at room temp
amino acids exist as zwitterions
so ionic bonds form between the zwitterions / amino acids
type of mechanism in kinetics
sn1 or sn2
no of species in rds
heterolytic bond fission
forms ions
zero order
constant rate
nitrile to amine
lialh4 dryether
halogenoalkne to amine
alcoholic ammonia
heat in sealed tube
