Chem 219: Module 2 UPDATED Questions
and CORRECT Answers
What are hydrocarbons? - CORRECT ANSWER✔✔- Molecules composed of only the
elements carbon and hydrogen
What are the two major classes of hydrocarbons? - CORRECT ANSWER✔✔- Aromatic
(benzene) and aliphatic (alkanes, alkenes, alkynes)
What is the main source of hydrocarbons? - CORRECT ANSWER✔✔- Fossil fuels like coal,
petroleum, and natural gas obtained by mining and drilling.
What are Alkanes? - CORRECT ANSWER✔✔- They are saturated hydrocarbons because
their skeleton is only composed of C-C single bonds.
How can alkanes exist? - CORRECT ANSWER✔✔- They can be linear, branched or exist in
ring formations called cycloalkanes.
Describe a higher/more complex alkane structure: - CORRECT ANSWER✔✔- They will
have more carbons and/or increased structural diversity.
What is the general formula of Alkanes? - CORRECT ANSWER✔✔- CnH2n+2
The names of the alkanes reflect? - CORRECT ANSWER✔✔- The number of carbons
present.
How many isomers does each alkane have from 1-10 - CORRECT ANSWER✔✔-
1,1,1,2,3,5,9,18,35,75
Name the first ten prefix of alkanes: - CORRECT ANSWER✔✔- Methane, ethane, propane,
butane, pentane, hexane, heptane, octane, nonane, decane.
,As the molecular weight increases: - CORRECT ANSWER✔✔- The number of isomers
increase.
What does the suffix -ane mean? - CORRECT ANSWER✔✔- Denotes a saturated
hydrocarbon. It is used for all acyclic saturated alkanes
What is nomenclature? - CORRECT ANSWER✔✔- The naming of a molecular structure.
Historically they were named after their source, now they are systemic.
Why is nomenclature important? - CORRECT 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? - CORRECT 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: - CORRECT 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? - CORRECT ANSWER✔✔- By combining the prefix
indicating the number to the suffix -ane.
What is a substituent? - CORRECT ANSWER✔✔- Any group attached to the parent chain.
What are alkyl groups? - CORRECT 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? - CORRECT ANSWER✔✔- A number used to determine the suffix.
Describes the position of substituents.
What happens when two or more of the same type of substituents are present on the parent
chain? Like 3 methyl groups - CORRECT ANSWER✔✔- Additional prefixes including the
number are added.
How would you describe finding 2,3 dimethylpentane? - CORRECT ANSWER✔✔- It is a 5
carbon chain, then it has substituents on numbers 2, 3 and those are methyl groups.
How are IUPAC systematic names put together? - CORRECT ANSWER✔✔- Locant-(prefix)
substituentparent
If two or more different substituents are present on the parent chain then what happens? -
CORRECT ANSWER✔✔- They are listed alphabetically. Ethyl before methyl
How are halogen atoms as substituents named? - CORRECT ANSWER✔✔- Change the -ine
to -o, chlorine=chloro, bromine=bromo.
propyl or n-propyl - CORRECT ANSWER✔✔- CH3CH2CH2
isopropyl - CORRECT ANSWER✔✔- CH3CHCH3
What does the squiggle bond mean? - CORRECT ANSWER✔✔- Point of attachment to the
parent chain.
Butyl or n-butyl - CORRECT ANSWER✔✔- -CH2CH2CH2CH3
sec-butyl - CORRECT ANSWER✔✔- CH3CHCH2CH3
isobutyl - CORRECT ANSWER✔✔-
and CORRECT Answers
What are hydrocarbons? - CORRECT ANSWER✔✔- Molecules composed of only the
elements carbon and hydrogen
What are the two major classes of hydrocarbons? - CORRECT ANSWER✔✔- Aromatic
(benzene) and aliphatic (alkanes, alkenes, alkynes)
What is the main source of hydrocarbons? - CORRECT ANSWER✔✔- Fossil fuels like coal,
petroleum, and natural gas obtained by mining and drilling.
What are Alkanes? - CORRECT ANSWER✔✔- They are saturated hydrocarbons because
their skeleton is only composed of C-C single bonds.
How can alkanes exist? - CORRECT ANSWER✔✔- They can be linear, branched or exist in
ring formations called cycloalkanes.
Describe a higher/more complex alkane structure: - CORRECT ANSWER✔✔- They will
have more carbons and/or increased structural diversity.
What is the general formula of Alkanes? - CORRECT ANSWER✔✔- CnH2n+2
The names of the alkanes reflect? - CORRECT ANSWER✔✔- The number of carbons
present.
How many isomers does each alkane have from 1-10 - CORRECT ANSWER✔✔-
1,1,1,2,3,5,9,18,35,75
Name the first ten prefix of alkanes: - CORRECT ANSWER✔✔- Methane, ethane, propane,
butane, pentane, hexane, heptane, octane, nonane, decane.
,As the molecular weight increases: - CORRECT ANSWER✔✔- The number of isomers
increase.
What does the suffix -ane mean? - CORRECT ANSWER✔✔- Denotes a saturated
hydrocarbon. It is used for all acyclic saturated alkanes
What is nomenclature? - CORRECT ANSWER✔✔- The naming of a molecular structure.
Historically they were named after their source, now they are systemic.
Why is nomenclature important? - CORRECT 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? - CORRECT 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: - CORRECT 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? - CORRECT ANSWER✔✔- By combining the prefix
indicating the number to the suffix -ane.
What is a substituent? - CORRECT ANSWER✔✔- Any group attached to the parent chain.
What are alkyl groups? - CORRECT 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? - CORRECT ANSWER✔✔- A number used to determine the suffix.
Describes the position of substituents.
What happens when two or more of the same type of substituents are present on the parent
chain? Like 3 methyl groups - CORRECT ANSWER✔✔- Additional prefixes including the
number are added.
How would you describe finding 2,3 dimethylpentane? - CORRECT ANSWER✔✔- It is a 5
carbon chain, then it has substituents on numbers 2, 3 and those are methyl groups.
How are IUPAC systematic names put together? - CORRECT ANSWER✔✔- Locant-(prefix)
substituentparent
If two or more different substituents are present on the parent chain then what happens? -
CORRECT ANSWER✔✔- They are listed alphabetically. Ethyl before methyl
How are halogen atoms as substituents named? - CORRECT ANSWER✔✔- Change the -ine
to -o, chlorine=chloro, bromine=bromo.
propyl or n-propyl - CORRECT ANSWER✔✔- CH3CH2CH2
isopropyl - CORRECT ANSWER✔✔- CH3CHCH3
What does the squiggle bond mean? - CORRECT ANSWER✔✔- Point of attachment to the
parent chain.
Butyl or n-butyl - CORRECT ANSWER✔✔- -CH2CH2CH2CH3
sec-butyl - CORRECT ANSWER✔✔- CH3CHCH2CH3
isobutyl - CORRECT ANSWER✔✔-
