Core Organic Chemistry

Question 1

3 reasons carbon can form so many compounds.

Answer 1

• can form 4 covalent bonds with other atoms
• can form single, double or triple bonds
• can bond to other c atoms to form chains

Question 2

define hydrocarbon

Answer 2

A compound containing carbon and hydrogen only

Question 3

define aliphatic

Answer 3

relating to or denoting organic compounds in which carbon atoms form open chains

Question 4

define alicyclic

Answer 4

relating or denoting to organic compounds that combine rings and chains / cyclic and aliphatic properties

Question 5

define aromatic

Answer 5

organic compounds containing a planar unsaturated ring of atoms which is stabilised by the bonds forming the ring. possibly including a benzene ring

Question 6

define saturated

Answer 6

.a molecule or substance where the atoms are only linked with single bonds

Question 7

define unsaturated

Answer 7

.a molecule or substance containing non-single bonds

Question 8

define homologous series

Answer 8

a series of organic compounds which have the same functional group but with each succesive memberdiffering by one CH2

Question 9

define functional group

Answer 9

a group of atoms responsible for the characteristic rections of a compound

Question 10

General formula for alkanes

Answer 10

C(n)H(2n+2) (saturated chain)

Question 11

General formula for cycloalkanes

Answer 11

CnH2n (saturated circle of bonds)

Question 12

General formula for alkynes

Answer 12

C(n)H(2n-2) (includes a triple bond)

Question 13

skeletal formula

Answer 13

A simplified organic formula with hydrogen atoms removed from alkyl chains leaving just carbon skeleton and associated functional groups

Question 14

Displayed formula

Answer 14

The relative positioning of all the atoms in a molecule, including bonds between them

Question 15

Alkane (formula of functional group)

Answer 15

C-C

Question 16

Alkene functional group formula

Answer 16

C=C

Question 17

Haloalkane functional group formula

Answer 17

R-I
R-Cl
R-Br
etc.

Question 18

Alcohol functional group

Answer 18

• OH

- ol

Question 19

Aldehyde functional group

Answer 19

R-C(-H)=O
Trigonal planar structure where R is a C chain or a hydrogen

-al

Question 20

ketone functional group

Answer 20

R-C(-R)=O
R is only a C chain

-one

Question 21

Carboxcylic acid functional group

Answer 21

R-C(-OH)=O
R is a H or a C chain

-oic acid

Question 22

Define structural isomers

Answer 22

Same molecular formula but different Displayed formula

Question 23

3 types of structural isomers

Answer 23

Chain isomer
-hydrocarbon chain may be branched or unbranched
-stem names for these isomers are different
Position isomer
- The hydrocarbon chain stays the same in these isomers but the position of the functional group is found at different points along the chain
- the numbers are different
Functional group isomer
-The functional group is different
-the prefix or suffix is different in the naming eg, cyclo- and -enes could have the same molecular formula

Question 24

Define an Alkane

Answer 24

Saturated hydrocarbons

Question 25

General hydrocarbon of formula CxHy combustion

Answer 25

CxHy + (x + 1/4y)O2 —–> xCO2 + 0.5yH2O

Question 26

Why is incomplete combustion dangerous?

Answer 26

carbon monoxide is toxic and can cause death by preventing haemoglobin from carrying oxygen to respiring tissues
Because CO is colourless and odorless it can be difficult to detect

Question 27

Why are yellow flames from Bunsen burners yellow?

Answer 27

The yellowness is caused by glowing soot particles indicating incomplete combustion, the outside of any glassware used will become blackened with soot.

Question 28

Reaction of alkanes with halogens /HCl

Answer 28

Substitution reaction
CH4 + Br2 —–> CH3Br + HBr
UV light is required as it provides the energy to break initial bonds

Question 29

Define a radical //notaion

Answer 29

A radical is a species with an unpaired electron

A dot similar to a bullet point after the element

Question 30

Radical substitution 3 stages?

Answer 30

initiation, propagation, termination

Question 31

Radical substitution, stages, info and equations

Answer 31

• = to the bullet point thingy

Initiation stage
initiation generates radicals for the reaction
Br2 —-UV—–> 2Br*
UV light provides energy required for the HOMOLYTIC bond breaking of Br-Br
Because the covalent bond between the Br’s contains two shared electrons, when this bond is broken both atoms recieve one of the two shared electrons. Giving both atoms an unpaired electron and creating radicals

Propagation stage
for every radical used in this reaction a new radical is produced.
Br* + CH4 —> HBr + CH3*
CH3* + Br2 —–> CH3Br + Br*

Termination stage 
2 radicals combine to produce a product that is not  radical 
CH3*  + Br*  ----->   CH3Br
Br*   + Br * -----> Br2
CH3*  + CH3* ------> C2H6

Question 32

By reacting propane with bromine a chemist tried to make 1-bromo propane.
WHat mixture of products did he make and how were they formed?

Answer 32

1-bromopropane – formed by simple radical substitution
2-bromopropane – formed by substitution at a different point in the C chain
1,1(/1,2/1,3) -dibromopropane —was formed by further substitution
Hexane — when two C3H7* combined
1-bromohexane —- substitution of the hexane side product
2,3,5-tribromohexane – formed by multiple substitution of hexane side product

Question 33

3 limitations of radical substitution

Answer 33

-Further substitution can occur
-Substitution at different points of C chain can occur
- C chain may change length / double
It is difficult to synthesis only 1 product