Chapter 11: basic concepts of organic chemistry (11.2-11.5)

Question 1

3 ways to classify hydrocarbons

Answer 1

aliphatic - carbon atoms are joined together in unbranched chains, branched chains, or non-aromatic rings

alicyclic - carbon atoms joined together in a ring (cyclic) either with or without branches

aromatic - some or all of the atoms are found in a benzene ring

Question 2

what are the three homologous series of aliphatic hydrocarbons you need to be aware of

Answer 2

alkanes - saturated, CnH2n+2
alkenes - contain at least one C=C double bond, CnH2n
alkynes - contains at least one triple carbon-to-carbon bond

Question 3

naming hydrocarbons: stem

Answer 3

the stem indicated the number of carbon atoms in the longest continuous chain in the molecule
mother (meth-), eats (eth-), proper (prop-), butter (but-)

Question 4

naming hydrocarbons: prefix

Answer 4

prefix comes before the stem to indicate the presence of side chains or a functional group
e.g. if something started with 2, methyl then there would be a CH3 side chain on the second carbon

Question 5

naming hydrocarbons: suffix

Answer 5

suffix is added after the stem to indicate functional groups

e.g. alkanes -ane . alkenes -ene . alcohols (-OH) -anol .

Question 6

naming cyclic alkanes

Answer 6

same rules as aliphatic alkanes, but use the prefix cyclo- to show it has a ring structure

Question 7

naming alkenes

Answer 7

general formula: CnH2n
functional group: C=C
suffix: -ene

Question 8

naming alchohols

Answer 8

general formula: CnH2n+1OH
functional group: -OH
prefix: hydroxy-
suffix: -ol

Question 9

naming aldehydes

Answer 9

functional group: -CHO

suffix: -al

Question 10

naming ketones

Answer 10

general formula: CnH2nO

functional group: -C(CO)C-

Question 11

how to indicate a side chain in molecular formula

Answer 11

using brackets

Question 12

naming carboxylic acids

Answer 12

general formula: CnH2nO2
functional group: -COOH
suffix: -oic acid

Question 13

naming haloanklanes

Answer 13

functional group: -Cl, -Br, -I

prefix: chloro-, bromo-, iodo-

Question 14

naming amines

Answer 14

functional group: -NH2

prefix: amino-
suffix: -amine

Question 15

naming nitriles

Answer 15

functional group: -CN

suffix: -nitrile

Question 16

how to read a skeletal formula

Answer 16

a line represents a single bond, double line represents a double bond e.c.t
where 2 lines meet indicates a carbon atom
end of a line represents a -CH3 functional group
when there are any functional groups other than CH3, they must be drawn onto the skeletal formula

Question 17

can isomers have different functional groups

Answer 17

yes

molecules can have the same molecular formula but different structures and therefore different functional groups

Question 18

how are covalent bonds broken

Answer 18

by bond fission

Question 19

what are the two types of bond fission

Answer 19

homolytic fission

heterolytic fission

Question 20

homolytic fission

Answer 20

When the bond breaks, each of the bonded atoms takes on of the shared pair of electrons from the bond
Each atom now has a single unbounded electron therefore 2 radicals are formed

Question 21

heterolytic fission

Answer 21

When the bond breaks, one of the bonded atoms takes both the electrons from the bond.
Two ions are formed (the atom which took both electrons is negative and the other is positive)

Question 22

what is a reaction mechanism

Answer 22

shows how the reaction took place

indicated with curly arrows. Curly arrows show the movement of electron pairs when bonds are being broken or made

Question 23

what are the 3 types of reaction

Answer 23

addition: two reactants join together to form one product
substitution: an atom (or group of atoms) in a molecule is replaced by a different atom (or group of atoms)
Elimination: this involves the removal of a small molecule from a larger one ie. 1 reactant gives 2 products

Question 24

effect of branching on boiling point

Answer 24

Branching decreases the boiling point. As the length of carbon chain decreases (due to branching), the surface area of the compound will also decrease. Van der Waals dispersion force is proportional to the surface area. So the decrease of surface area lessens the ability of individual molecules to attract each other.

Question 25

naming esters

Answer 25

functional group: -COOC-

suffix: -oate