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Flashcards in Learning from mistakes Deck (25):

coproduct vs byproduct

coproducts are formed in the main reaction along with the desired product. byproducts are formed in unwanted side reactions.


sulfonate vs sulfonyl

sulfonate is charged (SO3-)
sulfonyl is not charged (SO3H)


solubility of Pb2+ salts

all insoluble and a white ppt apart from lead iodide, which is bright yellow, and lead nitrate, which is soluble.


effect of changing pressure on Kc

no change in the size of Kc


equation for the formation of the electrophile in nitration

2 H2SO4 + HNO3 => H3O+ + NO2+ + 2 HSO4-


how to obtain a pure sample of an organic solid from a reaction mixture

filter then recrystallise


is concentrated or dilute sulphuric acid required for esterification/



why is a diphenol more reactive than benzene so doesn't require a catalyst (for friedel craft's alkylation)

lone pairs of electrons from the OH groups become delocalised into the pi system, increasing electron density and making the diphenol more susceptible to electrophilic attack.


naming a carboxylic acid alkene

-enoic acid


3 methods for usefully processing waste polymers

- recycling
- combustion for energy production
- use as organic feedstock for plastic production


method for distillation and purification of an organic liquid

- shake and leave to settle in separating funnel
- separate layers by tapping off
- add a small amount of anhydrous sodium sulphate to the organic layer in a dry conical flask, then filter
- distil the organic layer, collect the fraction below and up to the boiling point of the liquid.


why may the theoretical yield for a reaction not be obtained? (5)

Loss of product from reaction vessels
Side reactions occurring
Impurities in reactants
Changes in temp and pressure
Reaction is an equilibrium system


solubility of nitrates

all nitrates are soluble


which cations always form soluble salts

Li+, Na+, K+, NH4+


solubility of Na+, Li+ and K+ salts

always soluble


solubility of sulphate salts

Ca2+, Ba2+ and Pb2+ all form white precipitates, the rest are soluble


solubility of hydroxide salts

groups 1 and 2 are soluble, the rest are insoluble. solubility of group 2 hydroxides increases down the group


solubility of carbonate salts

Li+, Na+, K+, NH4+ are all soluble
the rest are insoluble:
Ca2+, Ba2+, Fe2+, Pb2+, Zn2+ and Al3+ are all white.
Ag+ is yellow
Cu+ is blue-green


solubility of lead (Pb2+) salts

all insoluble except for the nitrate
all white except for lead iodide, which is yellow


solubility of ammonium salts

all soluble


solubility of chloride salts

all soluble except for AgCl - white, and PbCl2 - white


solubility of bromide salts

all soluble except for AgBr - cream, and PbBr2 - white


solubility of iodide salts

all soluble except for AgI - pale yellow, and PbI - bright yellow


why is the delocalised structure of benzene preferred to the kekule model, in terms of reactions of benzene?

Benzene/A undergoes substitution (more easily than addition)

mention of delocalised electrons (in A) 
Benzene/A does not undergo addition (readily) 
because it has no double bonds/alkene 
OR B undergoes addition 
because it has double bonds/alkene 


use ideas about reaction orders, RD steps and active sites to explain the shape of the rate-substrate concentration graph.

first part of graph
first order for substrate – related to shape (e.g. ‘graph shows
proportional’ / ‘linear’/ ‘rate doubles as conc. doubles’/
‘constant positive gradient’ AW) 
rds is equation 1 / substrate is in rds 
second part of graph
zero order for substrate 
rds is equation 2 (or no longer equation 1) / substrate no
longer in rds 
all active sites (on enzyme) full/ saturated 