CHEM 219 MODULE 2 PREMIUM EXAM
REVIEW WITH DETAILED QUESTIONS AND
ACCURATE ANSWERS
◉ What are the two major classes of hydrocarbons?
Answer: Aromatic (benzene) and aliphatic (alkanes, alkenes,
alkynes)
◉ What is the main source of hydrocarbons?
Answer: Fossil fuels like coal, petroleum, and natural gas obtained
by mining and drilling.
◉ What are Alkanes?
Answer: They are saturated hydrocarbons because their skeleton
is only composed of C-C single bonds.
◉ How can alkanes exist?
Answer: They can be linear, branched or exist in ring formations
called cycloalkanes.
◉ Describe a higher/more complex alkane structure:
Answer: They will have more carbons and/or increased structural
diversity.
,◉ What is the general formula of Alkanes?
Answer: CnH2n+2
◉ The names of the alkanes reflect?
Answer: The number of carbons present.
◉ How many isomers does each alkane have from 1-10
Answer: 1,1,1,2,3,5,9,18,35,75
◉ Name the first ten prefix of alkanes:
Answer: Methane, ethane, propane, butane, pentane, hexane,
heptane, octane, nonane, decane.
◉ As the molecular weight increases:
Answer: The number of isomers increase.
◉ What does the suffix -ane mean?
Answer: Denotes a saturated hydrocarbon. It is used for all acyclic
saturated alkanes
◉ What is nomenclature?
Answer: The naming of a molecular structure. Historically they
were named after their source, now they are systemic.
, ◉ Why is nomenclature important?
Answer: Because we cannot remember all the prefixes since a MF
composed of carbons can have several different patterns of
connectivity.
◉ What is it meant by the systemic approach?
Answer: There are now methods of naming molecules so that they
all have unique names. You can then determine the structure from
only the name and vice-versa.
◉ IUPAC rules for naming branced alkanes:
Answer: 1. Find the parent name by identifying the longest
continuous chain of carbons.
2. Number the parent chain. (begin at the end of the chain nearest
to the first branch.)
3. If there are two equally long continuous chains, select the one
with most branches.
4. If the first branch point is the same distance, choose the one
that gives the lowest substituents.
5. If the substituents are both equidistant then choose the
numbering so the substituent goes with the higher alphabetic
priority.
◉ How are linear alkanes named?
REVIEW WITH DETAILED QUESTIONS AND
ACCURATE ANSWERS
◉ What are the two major classes of hydrocarbons?
Answer: Aromatic (benzene) and aliphatic (alkanes, alkenes,
alkynes)
◉ What is the main source of hydrocarbons?
Answer: Fossil fuels like coal, petroleum, and natural gas obtained
by mining and drilling.
◉ What are Alkanes?
Answer: They are saturated hydrocarbons because their skeleton
is only composed of C-C single bonds.
◉ How can alkanes exist?
Answer: They can be linear, branched or exist in ring formations
called cycloalkanes.
◉ Describe a higher/more complex alkane structure:
Answer: They will have more carbons and/or increased structural
diversity.
,◉ What is the general formula of Alkanes?
Answer: CnH2n+2
◉ The names of the alkanes reflect?
Answer: The number of carbons present.
◉ How many isomers does each alkane have from 1-10
Answer: 1,1,1,2,3,5,9,18,35,75
◉ Name the first ten prefix of alkanes:
Answer: Methane, ethane, propane, butane, pentane, hexane,
heptane, octane, nonane, decane.
◉ As the molecular weight increases:
Answer: The number of isomers increase.
◉ What does the suffix -ane mean?
Answer: Denotes a saturated hydrocarbon. It is used for all acyclic
saturated alkanes
◉ What is nomenclature?
Answer: The naming of a molecular structure. Historically they
were named after their source, now they are systemic.
, ◉ Why is nomenclature important?
Answer: Because we cannot remember all the prefixes since a MF
composed of carbons can have several different patterns of
connectivity.
◉ What is it meant by the systemic approach?
Answer: There are now methods of naming molecules so that they
all have unique names. You can then determine the structure from
only the name and vice-versa.
◉ IUPAC rules for naming branced alkanes:
Answer: 1. Find the parent name by identifying the longest
continuous chain of carbons.
2. Number the parent chain. (begin at the end of the chain nearest
to the first branch.)
3. If there are two equally long continuous chains, select the one
with most branches.
4. If the first branch point is the same distance, choose the one
that gives the lowest substituents.
5. If the substituents are both equidistant then choose the
numbering so the substituent goes with the higher alphabetic
priority.
◉ How are linear alkanes named?
