organic compounds

Question 1

organic compounds

Answer 1

compound containing Carbon
except CO, Co2, H2Co3

Question 2

four basic homologous series

Answer 2

alkanes
alkenes
alcohol
carboxylic acid

Question 3

alkanes, alkenes
similarities

Answer 3

both hydrocarbons
- contain H, C
- mostly colourless

Question 4

prefixes
C
C2
C3
C4
C5
C6

Answer 4

meth-
eth-
prop-
but-
pent-
hex-

Question 5

alkanes v alkenes

Answer 5

alkanes
general formula: Cn H2n+2, n ≥ 1
functional group: none
end w/: -ane
saturated hydrocarbons

alkenes
general formula: Cn H2n, n ≥ 2
functional group: C=C
end w/: -ene
unsaturated hydrocarbons
more reactive, flammable than alkane cuz C=C more reactive, than C-C

prefixes are based on total no. of carbon

alkanes struct formula start w/ n = 1
alkenes struct formula start w/ n = 2

Question 6

drawing struct formula important

Answer 6

1. 1 carbon can ONLY take 4 bonds (4 sticks)
2. if diagram ask copy down struct formula must place hydrogen, carbon at same place
3. general formula for naming based on number of other “sticks” other than carbon.

I.e. C5h10br2 -ane (C5 and 12 other bonds)

Question 7

alcohol, carboxylic acid common property

Answer 7

not hydrocarbons

Question 8

alcohol properties

Answer 8

1. funct grp —OH (hydroxyl)
2. usally end w/ -anol (i.e. ethanol)
3. Cn H2n+1 OH, where n ≥ 1
4. all alcohol are neutral despite having O-H

alcohol struct formula start w/ n = 1

prefixes are based on total no. of carbon

Question 9

carbolyxic/organic acid properties

Answer 9

1. funct grp carboxyl
   C=O
   |
   O
   |
   H)
2. usually end w/ -anioc acid
3. Cn H2n+1 COOH, where n ≥ 0
4. all weak acids

carboxylic acid struct formula start w/ n = 0

prefixes are based on total no. of carbon

Question 10

wat to do w/ funct group

Answer 10

most times: add at end, struct formula

prefixes are based on total no. of carbon

Question 11

all homologous series…

Answer 11

add Ch2 to get to next

i.e. methanol Ch4OH + Ch2 =
ethanol, C2h5Oh

Question 12

how categorise into homologous series

Answer 12

1. funct grp
2. general form
3. successive unit differ, Ch2 unit

Question 13

4 reactions of alkanes

Answer 13

1. incomplete combustion (insufficient o2)
2. complete combustion (excess/enough o2)
3. substitution w/ halogens (typically) (2 reactant form 2 products)
4. Cracking

Question 14

6 reactions, alkenes

Answer 14

combustion
1. incomplete combustion (insufficient o2)
2. complete combustion (excess/enough o2)

addition (2 reactants added, form one product)
3. hydrogenation (add hydrogen)
4. (halogen)nation (add halogen) (i.e. iodinisation)
5. hydration (add steam h2o(g))
6. addition polymerisation

https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 27 chlorinisation

https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 28 hydration

addition req C=C

Most, but not all addition reaction result in formation of alkanes.

Question 15

hydrogenation reaction condition

Answer 15

Nickel as catalyst
200 deg celc

Question 16

halogenation conditions

Answer 16

alkene, no condition for halogenation

alkane, req UV light, substitution

Question 17

hydrogenation conditions

Answer 17

300 deg celc
pressure 60 atm
phosphoric (V) acid as catalyst
steam (must be steam, not h2o (l)!)

300 + 60 + 5

hydration -> less letter, 200degcelc
hydrogenation -> more letter, 300 deg celc, 60 atm pressure, phosphoric (V)

Question 18

carboxylic acid reactions

Answer 18

1. substitution w/ halogens (typically)
2. Cracking

no combustion.

Question 19

incomplete combustion typically give out…

complete combustion typically give out…

Answer 19

incomp
CO, H2o, sometimes Carbon (soot)

comp
h2o, co2

Question 20

substitution of methane w/ chlorine gas (halogen)
visualise + what needed

Answer 20

https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 26

req UV light
one of hydrogen atoms, methane, replace by halogen atom

Question 21

as molecular mass of
4 homologous series compounds increase,

Answer 21

more carbon, stronger intermolecular forces
mp, bp increase
more viscous (more resistance, flow)

change of state gas -> liquid -> solid
density increase

flammability decrease EXCEPT
- Carboxylic acid not flammable (acid)
- Alkenes: %tage carbon increase, not molecular mass increase, causes decrease flammability

carboxylic acid does not undergo combustion

Question 22

what require for cracking reaction

Answer 22

1. porous pot
2. catalyst: Al2O3/SiO2
3. high temp: at least 600deg celc
4. room pressure: 1 atm

Question 23

cracking definition

Answer 23

break down of large alkane -> smaller hydrocarbon,
always producing alkene

Question 24

3 uses of cracking

Answer 24

1. crack one of the components of fuel oil (mix of hydrocarbons) produce gasoline (petrol)
2. crack alkenes produce plastic
3. produce h2 (g)

Question 25

alkanes properties

Answer 25

1. lowest mp, bp

Question 26

what req for addition polymerisation

Answer 26

1. must contain funct grp: C=C bond (Carbon Carbon double bond) (saturated) ## Footnote saturated means contain C=C bond

Question 27

how distinguish saturated from unsaturated hydrocarbon **IMPT**

Answer 27

add Br2 (aq) saturated hydrocarbon/alkane: - Br2 (aq) reddish-brown bromine remain reddish brown. - **substitution reaction, decolourises after very long period time** unsaturated hydrocarbon/alkene/contains C=C bond: - Br2 (aq) reddish-brown bromine decolourised rapidly - **addition reaction**