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Flashcards in Organic Chem exam qs Deck (44)
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1

How to demonstrate ethene readily undergoes addition reaction with bromine water

-bubble/add ethene into bromine water (solution)
-brown bromine solution decolorised

2

would you expect benzene to readily undergo an addition reaction with bromine waer?

-no

-benzene is table/benzene has no double bonds/benzene bonds intermediate between double and single / benzene readily undergoes substitution

3

explain delocalised

-shared between more than two atoms / shared by more than one bonded pair of atoms / moving (not fixed) between one pair of bonded atoms and another

4

how many electrons in a benzene molecule are delocalised?

6

5

how many electrons in a benzene molecule are involved in sigma bonds between carbon atoms?

12

6

health hazard associated with benzene

carcinogenic

7

effect of adding tetraethyllead to an equimolar mixture of methane and chlorine exposed to weak sunlight

-reaction rate increases
-tetraethyllead acts as a catalyst / tetraethyllead provides ethyl free radicals

8

explain fractionation of crude oil

separation into components according to molecular size/by distillation

9

components of liquid petroleum gas

propane
butane

10

LPG

liquid petroleum gas

11

drawing propan-1-ol

draw a bond between the OH functional group when drawing molecules such as propan-1-ol just in case

12

why boiling pt of propanal is higher than that of butane

-propanal has dipole-dipole forces/propanal is polar/has a polar CO

-butane has weaker intermolecular forces/butane is non-polar

13

why boiling pt of ethanoic acid is higher than that of propan-1-ol

-ethanoic acid has stronger/more hydrogen bonding than propan-1-ol
-ethanoic acid has polar OH and CO bonds/has two polar groups
-propan-1-ol molecule only has a polar OH bond/one polar group

14

organic product of reaction of propanal with KMnO4

propanoic acid

15

spectroscopic technique that could help confirm identity of a sample of eugenol

IR spectrometry or spectroscopy

16

hydrocarbon gas produced by anaerobic bacterial decomposition of either animal waste or vegetation

methane

17

polymer of ethene

polyethene

18

how does the geometry around the carbon atoms change in the conversion of ethanol to ethene?

tetrahedral to planar

19

effect of presence of tetraethyllead in the conversion of ethane to chloroethane

incrases rate/speeds up reaction by providing ethyl free radicals

20

carbonyl group in an ester

it is the c and o (double bonded), does not count the single bond o

21

testing for aldehydes (2 methods)

-Mix Fehling's 1 and 2
-Add to aldehyde and mix
-Heat gently
-Blue soln to red ppt is positive result

OR

-Add Tollen's Reagent in clean test tube
-Add aldehyde, mix
-heat gently
-silver mirror is positive result

22

reactions of carboxylic acids

on table

23

test for unsaturation

Alkenes, alkynes decolourise bromine water

equation on table

24

safe disposal of sodium resides

on table

25

when naming alkenes

indicate where double bond is in IUPAC names

eg. 1-butene (bond on the end)

26

why catalytic cracking, dehydro etc are carried out

-inc octane number
-make more useful compounds

27

colour change as phenylmethanol is converted to benzoic acid, explain this colour change by reference to the transition metal used

purple to brown to colourless

MnO₄⁻ (Mn(IV)) changes to Mn²⁺ (Mn(II))

28

effect of adding tetraethyllead in conversion of alkane to chloroalkane

tetraethyllead increases rate by providing ethyl free radicals

29

"circle the carbonyl group in this ester"

circle both the C and the O (the double bonded one)

30

explain whether or not the kekule model correctly describes (i) the number, and (ii) the distribution
of pi electrons in benzene

(i) yes, each of the 3 double bonds has 2 pi electrons

(ii) electrons in benzene are delocalised