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Flashcards in Learning from mistakes Deck (24):
1

coproduct vs byproduct

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

2

sulfonate vs sulfonyl

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

3

solubility of Pb2+ salts

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

4

effect of changing pressure on Kc

no change in the size of Kc

5

equation for the formation of the electrophile in nitration

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

6

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

filter then recrystallise

7

is concentrated or dilute sulphuric acid required for esterification/

concentrated

8

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.

9

naming a carboxylic acid alkene

-enoic acid

10

3 methods for usefully processing waste polymers

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

11

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.

12

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

13

solubility of nitrates

all nitrates are soluble

14

which cations always form soluble salts

Li+, Na+, K+, NH4+

15

solubility of Na+, Li+ and K+ salts

always soluble

16

solubility of sulphate salts

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

17

solubility of hydroxide salts

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

18

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

19

solubility of lead (Pb2+) salts

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

20

solubility of ammonium salts

all soluble

21

solubility of chloride salts

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

22

solubility of bromide salts

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

23

solubility of iodide salts

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

24

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 