What is an empirical formula?
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What is an empirical formula?
An empirical formula is the simplest whole-number ratio of the atoms in a molecule.
Define molecular formula.
A molecular formula shows the actual number of each atom in a molecule.
True or False?
The molecular formula of butane is C2H5.
False.
The empirical formula of butane is C2H5.
The molecular formula of butane is C4H10.
What does a structural formula show?
A structural formula shows the spatial arrangement of all the atoms and bonds in a molecule.
What is a condensed structural formula?
A condensed structural formula is a formula that shows enough information to make the structure clear, but omits most of the actual covalent bonds.
Define skeletal formula.
A skeletal formula is a simplified displayed formula where carbon-carbon bonds are represented by lines, carbon atoms are at the end of each line or where lines meet, and most hydrogen atoms are removed.
What does a stereochemical formula show?
A stereochemical formula shows the relative positions and three-dimensional geometry of atoms and groups of atoms around a chiral carbon.
In a stereochemical formula, what do solid wedges represent?
In a stereochemical formula, solid wedges represent bonds coming forward, out of the plane.
True or False?
The empirical formulae of ethene, propene and butene are the same.
True.
The empirical formulae of ethene, propene and butene are all CH2.
What is the shape of a chiral carbon with four different groups attached?
The shape of a chiral carbon with four different groups attached is tetrahedral with bond angles of 109.5°.
Write the condensed structural formula of propane.
The condensed structural formula of propane is CH3CH2CH3.
Draw the skeletal formula of propene.
The skeletal formula of propene is:
True or False?
The stereochemical formula of 1-chloroethan-1-ol is:
False.
The stereochemical formula of 1-chloroethan-1-ol is:
True or False?
The structural formula of ethanol is:
False.
The structural formula of a chemical has all of the chemical bonds displayed, which means that ethanol is:
What are functional groups in organic chemistry?
Functional groups are atoms or groups of atoms that are found in organic compounds and give them their characteristic physical and chemical properties.
True or False?
Organic compounds with the same functional group belong to the same class.
True.
Organic compounds with the same functional group belong to the same class.
What is the functional group of an alkene?
The functional group of an alkene is the carbon-carbon double bond (C=C).
What is the functional group for a carboxylic acid?
The functional group for a carboxylic acid is -COOH.
True or False?
The IUPAC suffix for a ketone is -one.
True.
The IUPAC suffix for a ketone is -one.
State the functional group, IUPAC prefix and IUPAC suffix for an amine.
For an amine:
Functional group = -NH2
IUPAC prefix = amino-
IUPAC suffix = -amine
Define the term phenyl.
Phenyl is the functional group name for aromatic compounds, implying that a benzene ring is present.
State the functional group, IUPAC prefix and IUPAC suffix for an alcohol.
For an alcohol:
Functional group = -OH
IUPAC prefix = hydroxy-
IUPAC suffix = -ol
True or False?
The functional group formula for an ester is R-COO-R.
True.
The functional group formula for an ester is R-COO-R.
Which functional group is present in aldehydes and ketones?
The carbonyl functional group (C=O) is present in aldehydes and ketones.
True or False?
The functional group formula for an alkoxy compound is R-O-R.
True.
The functional group formula for an alkoxy compound is R-O-R.
What is the suffix for carboxylic acids?
The suffix for carboxylic acids is -oic acid.
Which class of organic molecules contain the following functional group?
Amides / amido compounds contain the following functional group.
Define the term homologous series.
A homologous series is a series or family of organic compounds that have similar features and chemical properties due to having the same functional group.
True or False?
A functional group is a group of atoms bonded in a specific arrangement that influences the properties of the homologous series.
True.
A functional group is a group of atoms bonded in a specific arrangement that influences the properties of the homologous series
Give two characteristics of a homologous series.
All members of a homologous series have:
The same general formula
Same functional group
Similar chemical properties
A clear trend in their physical properties
The difference in the molecular formula between one member and the next is CH2
Which homologous series contains only carbon-hydrogen bonds and saturated carbon-carbon bonds?
The homologous series of alkanes contains only carbon-hydrogen bonds and saturated carbon-carbon bonds.
True of False?
The alkene functional group is represented by C-C.
False.
The alkene functional group is represented by C=C.
State the general formula for alkanes.
The general formula for alkanes is CnH2n+2.
What is the general formula for alkenes?
The general formula for alkenes is CnH2n.
Which homologous series has the general formula CnH2n+1OH?
The homologous series of alcohols has the general formula CnH2n+1OH.
True or False?
The general formula of carboxylic acids is CnH2n+1CHO.
False.
The general formula of the carboxylic acids is CnH2n+1COOH.
The general formula of an aldehyde is CnH2n+1CHO.
True or False?
Each homologous series can be described by a molecular formula.
False.
Each homologous series can be described by a general formula.
True or False?
As the number of carbons in a straight-chain molecule increases, the boiling point decreases.
False.
As the number of carbons in a straight-chain molecule increases, the boiling point increases.
What causes the increase in boiling point as the molecular size increases in a homologous series?
In a homologous series, boiling point increases with molecular size due to the increased strength of London dispersion forces.
True or False?
Physical properties such as melting point, density, and viscosity show similar trends to boiling point in a homologous series.
True.
Physical properties such as melting point, density, and viscosity show similar trends to boiling point in a homologous series.
What is the general formula of halogenoalkanes?
The general formula of halogenoalkanes is CnH2n+1X.
True or False?
Aldehydes and ketones have the same general formula.
True.
Aldehydes and ketones have the same general formula of CnH2nO.
True or False?
The general formula of an alkyne is CnH2n+2.
False.
The general formula of an alkyne is CnH2n-2.
Name two homologous series that contain nitrogen in their general formula, and state their general formula.
Two homologous series, with general formula, that contain nitrogen include:
Amines - CnH2n+1NH2
Amides - CnH2n+1NO
Which homologous series has the general formula CnH2nO2?
The homologous series of esters has the general formula CnH2nO2.
Which homologous series does the following compound belong to?
The following compound belongs to the homologous series of ethers.
Name three homologous series that contain a carbonyl, C=O, bond.
Homologous series that contain a carbonyl, C=O, bond include:
Aldehydes
Ketones
Carboxylic acids
Amides
Esters
What does the prefix tell you in the name of a hydrocarbon?
The prefix tells you the number of carbon atoms in the longest continuous chain in the hydrocarbon.
How many carbon atoms are in a carbon chain if the prefix is prop-?
There are three carbon atoms in the carbon chain if the prefix is prop-.
What does the suffix tell you in the name of a molecule?
The suffix tells you what functional group is on the compound.
What is the name of this compound?
CH3CH2CH2CH2OH
The name of CH3CH2CH2CH2OH is butan-1-ol.
What is the name of this compound?
CH3CH2CH2CH2CH3
The name of CH3CH2CH2CH2CH3 is pentane.
What is the name of this compound?
CH3CH2COOH
The name of CH3CH2COOH is propanoic acid.
What is the name of the this compound?
CH3(CH2)3HC=CH2
The name of CH3(CH2)3HC=CH2 is hex-1-ene.
True or False?
The name of CH3COOCH2CH3 is ethyl methanoate.
False.
The name of CH3COOCH2CH3 is ethyl ethanoate.
The two carbon atoms highlighted (in bold) come from the carboxylic acid used to form the ester.
True or False?
Numbering in organic compound names always starts from the left.
False.
Numbering in organic compound names sometimes starts from the right to keep the numbers as low as possible.
Certain functional groups such as aldehydes, CHO, and carboxylic acids, COOH, normally have their carbon atom labelled as carbon-1.
What is the name of the following alcohol?
The name of the following alcohol is butan-2-ol.
True or False?
The prefix "eth-" is used for compounds with three carbon atoms.
False.
The prefix "eth-" is used for compounds with two carbon atoms.
The prefix "prop-" is used for compounds with three carbon atoms.
What is an alkyl group?
An alkyl group is a hydrocarbon side chain, named by adding '-yl' to the normal alkane stem.
How are multiple identical side chains indicated in IUPAC nomenclature?
Multiple identical side chains are indicated by using prefixes di- (for two), tri- (for three), or tetra- (for four).
True or False?
When naming alkenes, the carbon atoms are numbered starting with the end closest to the double bond.
True.
In naming alkenes, the carbon atoms are numbered starting with the end closest to the double bond.
How are halogenoalkanes named in IUPAC nomenclature?
Halogenoalkanes are named using:
The appropriate prefix fluoro-, chloro-, bromo- or iodo-, with a number to identify the carbon it is attached to in the chain
The appropriate name to identify the longest carbon chain
The suffix -ane to show that the halogenoalkane is saturated
Explain the name of the following organic compound.
The following organic compound is 3-hydroxypropanoic acid.
The carboxylic acid carbon is automatically carbon-1, which means the name ends in -oic acid.
The hydroxyl group is attached to carbon-3, which means the name starts with 3-hydroxy.
The chain is 3 carbons long and contains only single bonds, which means the name contains propan.
3-hydroxy + propan + oic acid = 3-hydroxypropanoic acid.
What are isomers?
Isomers are compounds that have the same molecular formula but a different arrangement of atoms.
Define structural isomers.
Structural isomers are compounds that have:
The same molecular formulae
But different structural formulae.
What are the three types of structural isomerism?
The three types of structural isomerism are:
Functional group isomerism
Positional isomerism
Branched chain isomerism.
What is functional group isomerism?
Functional group isomerism is when different functional groups result in the same molecular formula.
True or False?
Alcohols and ethers can be functional group isomers of each other.
True.
Alcohols and ethers can be functional group isomers of each other.
True or False?
Aldehydes and carboxylic acids are functional group isomers of each other.
False.
Aldehydes and ketones are functional group isomers of each other.
What is positional isomerism?
Positional isomerism is where isomers have the same functional group in different positions on the carbon chain.
True or False?
Branched chain isomerism is when compounds have the same molecular formula, but their longest hydrocarbon chain is not the same.
True.
Branched chain isomerism is when compounds have the same molecular formula, but their longest hydrocarbon chain is not the same.
Describe a primary alcohol.
A primary alcohol is an alcohol where the carbon atom attached to the -OH group is also attached to only one other carbon atom
True or False?
In amines, primary, secondary, and tertiary refer to the number of hydrogen atoms attached to the nitrogen.
False.
In amines, primary, secondary, and tertiary refer to the number of carbon atoms (or alkyl groups) attached to the nitrogen.
What is the smallest number of carbon atoms required for an alkane to exhibit branched chain isomerism?
The smallest number of carbon atoms required for an alkane to exhibit branched chain isomerism is four.
What organic compounds are functional group isomers of alkenes?
Cyclic alkanes / cycloalkanes are functional group isomers of alkenes.
Why are hexan-2-ol and ethoxypropane not functional group isomers of each other?
Hexan-2-ol, C6H14O, and ethoxypropane, C5H12O, are not functional group isomers of each other because they have different molecular formulae.
Draw the positional isomer of propan-2-ol.
The positional isomer of propan-2-ol is propan-1-ol:
Which organic compound is a functional group isomer of cyclobutane and a position isomer of but-2-ene?
But-1-ene is a functional group isomer of cyclobutane and a position isomer of but-2-ene.
Draw and name the branched isomer of butane.
The branched isomer of butane is methylpropane:
Explain whether the position isomer of 2-chloro-2-methylpropane is a primary, secondary or tertiary halogenoalkane.
The position isomer of 2-chloromethylpropane is a primary halogenoalkane because the halogen is bonded to a carbon atom that is attached to only one other carbon atom.