CHEM 219: MODULE 2 EXAM (ACTUAL 2025)
WITH VERIFIED ANSWERS
What are hydrocarbons? - <<<,Answers>>>Molecules
composed of only the elements carbon and hydrogen
What are the two major classes of hydrocarbons? -
<<<,Answers>>>Aromatic (benzene) and aliphatic (alkanes,
alkenes, alkynes)
Describe a higher/more complex alkane structure: -
<<<,Answers>>>They will have more carbons and/or
increased structural diversity.
What is the general formula of Alkanes? -
<<<,Answers>>>CnH2n+2
The names of the alkanes reflect? - <<<,Answers>>>The
number of carbons present.
How many isomers does each alkane have from 1-10 -
<<<,Answers>>>1,1,1,2,3,5,9,18,35,75
,Name the first ten prefix of alkanes: -
<<<,Answers>>>Methane, ethane, propane, butane, pentane,
hexane, heptane, octane, nonane, decane.
As the molecular weight increases: - <<<,Answers>>>The
number of isomers increase.
What does the suffix -ane mean? - <<<,Answers>>>Denotes a
saturated hydrocarbon. It is used for all acyclic saturated
alkanes
What is nomenclature? - <<<,Answers>>>The naming of a
molecular structure. Historically they were named after their
source, now they are systemic.
Why is nomenclature important? - <<<,Answers>>>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? -
<<<,Answers>>>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: -
<<<,Answers>>>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? - <<<,Answers>>>By
combining the prefix indicating the number to the suffix -ane.
What is a substituent? - <<<,Answers>>>Any group attached
to the parent chain.
What are alkyl groups? - <<<,Answers>>>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? - <<<,Answers>>>A number used to
determine the suffix.
WITH VERIFIED ANSWERS
What are hydrocarbons? - <<<,Answers>>>Molecules
composed of only the elements carbon and hydrogen
What are the two major classes of hydrocarbons? -
<<<,Answers>>>Aromatic (benzene) and aliphatic (alkanes,
alkenes, alkynes)
Describe a higher/more complex alkane structure: -
<<<,Answers>>>They will have more carbons and/or
increased structural diversity.
What is the general formula of Alkanes? -
<<<,Answers>>>CnH2n+2
The names of the alkanes reflect? - <<<,Answers>>>The
number of carbons present.
How many isomers does each alkane have from 1-10 -
<<<,Answers>>>1,1,1,2,3,5,9,18,35,75
,Name the first ten prefix of alkanes: -
<<<,Answers>>>Methane, ethane, propane, butane, pentane,
hexane, heptane, octane, nonane, decane.
As the molecular weight increases: - <<<,Answers>>>The
number of isomers increase.
What does the suffix -ane mean? - <<<,Answers>>>Denotes a
saturated hydrocarbon. It is used for all acyclic saturated
alkanes
What is nomenclature? - <<<,Answers>>>The naming of a
molecular structure. Historically they were named after their
source, now they are systemic.
Why is nomenclature important? - <<<,Answers>>>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? -
<<<,Answers>>>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: -
<<<,Answers>>>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? - <<<,Answers>>>By
combining the prefix indicating the number to the suffix -ane.
What is a substituent? - <<<,Answers>>>Any group attached
to the parent chain.
What are alkyl groups? - <<<,Answers>>>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? - <<<,Answers>>>A number used to
determine the suffix.
