Naming organic compounds

Question 1

What is the order of alkanes and what are their formulas?

Answer 1

methane - CH4
ethane - C2H6
propene - C3H8
butane - C4H10
pentane - C5H12
hexane - C6H14
heptane
octane
non
dec

Question 2

What is the general formula for alkanes?

Answer 2

Cn H2n + 2

Question 3

Define isomers

Answer 3

molecules with the same chemical formula but diff structures

Question 4

Define structural isomers

Answer 4

• molecules with same molecular formula
• but diff structural formula

Question 5

Define chain isomers

Answer 5

• molecules with same molecular formula
• but diff displayed formula

Question 6

What are the steps to naming branched alkanes?

Answer 6

• find the longest chain - name as usual
• find any side chains - name them by looking at the positions (use prefixes for number of carbon atoms + end in yl)
• the side branches are the same use:
• di = 2
• tri = 3
• tetra = 4
• penta - 5
• hexa = 6
• hepta = 7
• octa = 8

Question 6

Define functional group isomerism

Answer 6

• molecules with same molecular formula
• but diff functional groups

Question 6

Define positional isomers

Answer 6

• molecules with same molecular formula
• with functional groups on diff positions in molecule

Question 7

What is the general formula for alkenes?

Answer 7

Cn H2n

Question 8

What is the order of alkenes and what are their formulas?

Answer 8

ethene - C2H4
propene - C3H6
butene - C4H8
pentene - C5H10
hexene - C6H12
heptene
octene
nonone
decene

Question 9

What type of bonds do saturated alkanes have?

Answer 9

C - C single bond

Question 10

What type of bonds do unsaturated alkenes have?

Answer 10

C = C double bond

Question 11

What are E - Z isomers?

Answer 11

If you have 2 diff groups attached to a C of C=C in alkenes, this is an E - Z isomer

Question 12

What is it called if the E-Z isomers are on the same side?

Answer 12

CIS

Question 13

What is it called if the E-Z isomers are on opposite sides?

Answer 13

TRANS

Question 14

View booklet to see how to name alkenes + dienes

Answer 14

page 11 and12

Question 15

How do you name cycloalkanes and cycloalkenes?

Answer 15

• count the carbon atoms
• name the alkene
• add cyclo onto beginning of name

Question 16

Define stereoisomers

Answer 16

• molecules with the same structural formula
• but different arrangement of atoms in space

Question 17

why do stereoisomers occur?

Answer 17

restricted rotation around C = C give rise to cis (Z) / trans (E)

Question 18

Describe the reactivity of alkenes vs alkanes

Answer 18

• C=C (alkenes) is stronger than C - C
• sigma bond is stronger than pie bond
• C = C contains sigma and pie bond, C - C contains just sigma bond
• alkenes are more reactive as they have double bonds

Question 19

What are the names of the multipliers used when more than one side chain is the same

Answer 19

Di
Tri
Tetra
Penta
Hexa
Hepta
Octa