CHEM 219: MODULE 2 EXAM (ACTUAL 2025) WITH VERIFIED ANSWERS

CHEM 219: MODULE 2 EXAM (ACTUAL 2025)
WITH VERIFIED ANSWERS


What are hydrocarbons? - ..>> CORRECT ANSWERS
>>Molecules composed of only the elements carbon and
hydrogen


What are the two major classes of hydrocarbons? -
..>> CORRECT ANSWERS >>Aromatic (benzene) and
aliphatic (alkanes, alkenes, alkynes)
Describe a higher/more complex alkane structure: -
..>> CORRECT ANSWERS >>They will have more carbons
and/or increased structural diversity.


What is the general formula of Alkanes? -
..>> CORRECT ANSWERS >>CnH2n+2

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,The names of the alkanes reflect? - ..>> CORRECT
ANSWERS >>The number of carbons present.


How many isomers does each alkane have from 1-10 -
..>> CORRECT ANSWERS >>1,1,1,2,3,5,9,18,35,75




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,Name the first ten prefix of alkanes: -
..>> CORRECT ANSWERS >>Methane, ethane, propane,
butane, pentane, hexane, heptane, octane, nonane, decane.


As the molecular weight increases: - ..>> CORRECT
ANSWERS >>The number of isomers increase.


What does the suffix -ane mean? - ..>> CORRECT
ANSWERS >>Denotes a saturated hydrocarbon. It is used for
all acyclic saturated alkanes


What is nomenclature? - ..>> CORRECT ANSWERS >>The
naming of a molecular structure. Historically they were named
after their source, now they are systemic.


Why is nomenclature important? - ..>> CORRECT
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? -
..>> CORRECT 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.


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, IUPAC rules for naming branced alkanes: -
B B B B B B



B..>> CORRECT ANSWERS >>1. Find the parent name by
B B B B B B B B



Bidentifying the longest continuous chain of carbons.
B B B B B B




2. Number the parent chain. (begin at the end of the chain
B B B B B B B B B B



nearest to the first branch.)
B B B B B




3. If there are two equally long continuous chains, select the
B B B B B B B B B



one with most branches.
B B B B




4. If the first branch point is the same distance, choose the one
B B B B B B B B B B B



that gives the lowest substituents.
B B B B B




5. If the substituents are both equidistant then choose the
B B B B B B B B



numbering so the substituent goes with the higher alphabetic
B B B B B B B B B



priority.
B




How are linear alkanes named? - ..>> CORRECT
B B B B B BB B



ANSWERS >>By combining the prefix indicating the
B B B B B B B



number to the suffix -ane.
B B B B B




What is a substituent? - ..>> CORRECT ANSWERS >>Any
B B B B BB B B B



group attached to the parent chain.
B B B B B B




What are alkyl groups? - ..>> CORRECT ANSWERS
B B B B BB B B



>>Saturated hydrocarbon substituents. You drop the -yl for -
B B B B B B B B B



ane.
A one carbon substituent is a methyl group, four carbon is
B B B B B B B B B B



butyl.
B




What is a locant? - ..>> CORRECT ANSWERS >>A number
B B B B BB B B B B




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