CHEM219 MODULE 7 2026 FINAL ASSESSMENT
TESTED CONTENT WITH ACCURATE
SOLUTIONS
◉ 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? Answer: By combining the prefix
indicating the number to the suffix -ane.
◉ What is a substituent? Answer: Any group attached to the parent
chain.
◉ What are alkyl groups? Answer: Saturated hydrocarbon
substituents. You drop the -yl for -ane.
A one carbon substituent is a methyl group, four carbon is butyl.
◉ What is a locant? Answer: A number used to determine the suffix.
TESTED CONTENT WITH ACCURATE
SOLUTIONS
◉ 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? Answer: By combining the prefix
indicating the number to the suffix -ane.
◉ What is a substituent? Answer: Any group attached to the parent
chain.
◉ What are alkyl groups? Answer: Saturated hydrocarbon
substituents. You drop the -yl for -ane.
A one carbon substituent is a methyl group, four carbon is butyl.
◉ What is a locant? Answer: A number used to determine the suffix.
