Mr. Storie
Organic –Unit Review KEY
30S Chemistry
Organic Unit Review KEY
1. Draw complete structural formulas for alkanes with two and six carbons. Name the structures.
Ethane
Hexane
2. Draw condensed structural formulas for pentane and heptane.
CH3CH2CH2CH2CH3
CH3CH2 CH2CH2 CH2CH2CH3
3. Name the compounds that follow:
a.
3,3-dimethylhexane
b.
2,4-dimethylhexane
c. 2,2,4,4-tetramethylpentane
d. 3-ethylhexane
e. 3-methylpentane
Mr. Storie
30S Chemistry
Organic –Unit Review KEY
a.
b.
c.
d.
e.
f.
4. Draw complete structural formulas for the following compounds:
3-ethyl-2,4-dimethyloctane
2,2,4-trimethylpentane
3-ethylhexane
3,5-diethyl-2,3-dimethyl-5-propyldecane
propyne
cyclopentane
a.
b.
c.
d.
5. Draw the structural formulas for the following alkenes. If a compound has geometric isomers, draw
both the cis and trans forms.
1-pentene
2-hexene
2-methyl-2-hexene
2,3-dimethyl-2-butene
Mr. Storie
30S Chemistry
Organic –Unit Review KEY
6. Name the following compounds:
propylbenzene
2-phenylpropane
2,5-dimethyl-3-phenylhexane
7. Why are the following names incorrect?
a. 2-dimethylpentane – since it is “dimethyl” it should have either a second number placement (2,2) or
only be a single methyl group (2-methyl).
b. 1,3-dimethylpropane – with methyl groups off the first and third of a propane chain, it would actually
be a 5-C long chain and thus better named pentane.
c. 3-methylbutane – it would be better to number carbons from the other end, making this 2methylbutane.
d. 3,4-dimethylbutane – two problems: a methyl group off the 4th and final carbon of a butane extends
the long chain which means this is actually pentane. A re-numbering of the chain then leaves only 1
methyl group at the 3, giving 3-methylpentane.
8. Explain the difference between saturated and unsaturated hydrocarbon compounds.
Saturated is an alkane – all single bonds – all possible bonds filled with hydrogen
Unsaturated is an alkene/yne – double or triple bonds – not completely full of possible hydrogen
9. Draw all the possible alkenes with the molecular formula C4H8. Name each compound.
Mr. Storie
Organic –Unit Review KEY
30S Chemistry
10. Explain why alkenes have cis/trans isomers and alkanes don’t.
Double bonds can’t rotate. Single can – branches can be pointing up or down and move between.
Double bonded branches are EITHER up or down pointing and can’t rotate.
a.
b.
c.
d.
11. Draw a structure for each compound.
p – diethylbenzene
2-methyl-3-phenylpentane
p-xylene
toluene
12. Write a complete balanced equation for the combustion of pentane.
C5H12 + 8 O 2  5 CO2 + 6 H2O
13. Name the following compounds:
a.
b.
c.
d.
2-methyl-2-butene
2-methypentene
2-butene
cis 3-methyl-2-pentene
Mr. Storie
Organic –Unit Review KEY
30S Chemistry
14. Name the following compounds:
a.
b.
c.
d.
e.
d. CH3CH2CH2CH2OH
a.
b.
c.
d.
e.
f.
15. Give the structural formula for each of the following compounds:
2-chloropropane
1-iodo-2,2-dimethylpentane
p-dibromobenzene.
2-methylphenol
1,2-dichlorocyclohexane
1,2-ethandiol
bromobenzene
chloroethane
3-chlorobutene
Butanol
2-propanol
Mr. Storie
a.
b.
c.
d.
e.
f.
Organic –Unit Review KEY
30S Chemistry
16. Give the name for the following carboxylic acids and esters:
HCOOH
Methanoic acid
CH3CH2COOH
Propanoic acid
CH3COOCH2CH3
Ethyl ethanoate
CH3COOH
Ethanoic acid
CH3(CH2)4COOH
Hexanoic acid
CH3CH2CH2COOCH2CH3
Ethyl butanoate
17. Use the ester from question 16c to show a complete de-esterification reaction.
 CH3COOH
ethanoic acid
H2O + CH3COOCH2CH3
water ethyl ethanoate
+ HO-CH2CH3
ethanol
18. Use 2-butene to show a hydration reaction.
CH3CH=CHCH3 + H2O 
2-butene
water
CH3CH(OH)CH2CH3
2-butanol
19. Write the structure for the reactants and expected products from each reaction:
a. propene + bromine gas 
CH2=CHCH3
propene
+ Br2
 CH2(Br)CH(Br)CH3
bromine
2,3-dibromopropane
b. 2-pentene + iodine gas 
CH3CH=CHCH2CH3 + I2 
2-pentene
iodine
CH3CH(I)CH(I)CH2CH3
2,3-diiodopentane
c. 3-octyne + hydrogen gas 
CH3CH2CΞCCH2CH2CH2CH3 + H2 
3-octyne
hydrogen
CH3CH2CH=CHCH2CH2CH2CH3
3-octene
Or…if you used 2 moles of H2 the product would have been octane.
d. trans 2-butene + hydrogen gas 
CH3
CH=CH
CH3
trans 2-butene
+
H2
hydrogen

CH3CH2CH2CH3
butane