IB Chemistry (SL) - Organic Chemistry - Homologous series and Functional Groups Practice

What are functional groups?

a group of atoms responsible for the characteristic reactions of a particular compound.

specific groups of atoms that have characteristic chemical properties

Molecules that have the same functional group (with different length of carbon chain) are said to belong to the same…

…homologous series

What is a homologous series?

A family of organic compounds that have the same functional group, similar chemical properties and the same general formula

What is an alkane?

A saturated (single bonds only) hydrocarbon

What is an alkyl group?

It is an alkane molecule with one hydrogen atom missing; it doesn't exist on its own, but is part of another molecule.

Which homologous series contains an alkyl functional group?

Homologous series: alkane

C - C

Which functional group does the homologous series alkanes contain?

Functional group: alkyl

C - C

Which homologous series contains an alkenyl functional group?

Homologous series: alkene

C = C

What is an alkene?

An unsaturated hydrocarbon with a carbon-carbon double bond

What is an alkenyl group?

Which functional group does the homologous series alkene contain?

Functional group: alkenyl

C = C

Which homologous series contains an alkynyl functional group?

Homologous series: alkyne

C≡C

What is an alkyne?

An unsaturated hydrocarbon with a triple bond

What is an alkynyl group?

Which homologous series contains an alkynyl function group?

Homologous series: alkyne

C≡C

Which functional group does the homologous series alkyne contain?

Functional group: alkynyl

C≡C

What is a halogenoalkane?

An alkane (saturated hydrocarbon) with at least one halogen atom in place of a hydrogen atom (halogen bonded to at least one carbon atom

F, Cl, Br, I --> fluoro, chloro, bromo, iodo

represented by RX

Where R can be any hydrocarbon (alkyl) group

What is a halo group?

One of the halogens (chlorine, bromine etc.)

What does the -x stand for? e.g. C-X (halogenoalkane)

One of the halogens, for example in a halogenoalkane, it could be any of the halogens, however we don't know which one it is, so we represent the possibilities with X (could be any one of them)

Which homologous series contains a halo (chloro, brom etc.) functional group?

Homologous series: halogenoalkane

C - X

Which functional group does the homologous series halogenoalkane contain?

Functional group: halo (chloro, bromo etc.)

C - X

How do you name a halogenoalkane?

Naming: use "halo-" prefix, i.e., fluoro-, chloro-, bromo-, iodo-

Write the condensed structural formula for iodoethane.

ICH2CH3

Draw the full structural formula iodoethane

Name this hydrocarbon

Write the condensed structural formula for 2-bromo, 1-chloropropane****ask for how to do this

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Draw the full structural formula for 2-bromo, 1-chloropropane

Name this hydrocarbon

Draw the full structural formula for bromochlorodifluoromethane

Name this hydrocarbon

Write the condensed structural formula for bromochlorodifluoromethane***

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Draw the skeletal structure for 1,1,2-Trichloroethene

Name this hydrocarbon

Write the condensed structural formula for 1,1,2-Trichloroethene***

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Draw the full structural formula for decafluorobutane.

C-C-C-C (with F one each carbon (as if was normal butane)

Write the condensed structural formula for decafluorobutane. ***

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What is an alcohol (series)?

Contain an -OH (hydroxyl) group attached to a carbon atom

--> represented by "ROH" where R can be any hydrocarbon (alkyl) group

How do you name an alcohol?

drop the -e from the -ane/-ene/-yne suffix

Use the suffix "-ol"

e.g., ethanol (R = CH3CH2)

If "di", "tri", "tetra" etc is used before the suffix,an e is placed after the n

e.. butane-2,3-diol

What happens when there are two functional groups in the organic molecule? e.g. a carboxyl functional group and a hydroxyl functional group

• The hydroxyl functional now forms the prefix component of the name.

• The carboxyl is more reactive functional group and is therefore assigned the suffix "oic acid" in the molecules name.

Name: 5-hydroxypentanoic acid

Draw the skeletal structure for 3-hydroxyhexanoic acid a hydroxyl functional group

Name this hydrocarbon

Draw the skeletal structure for 4,4-dihydroxybutanoic acid

Name this hydrocarbon

Draw the skeletal structure for 3,4-dihydroxybutanoic acid

Name this hydrocarbon

Draw the full structural formula for butan-1-ol

Name this alcohol

Draw the full structural formula for butan-2-ol

Name this alcohol, C4H9OH

There are two forms of butanaol that are structurally different (2 isomers). What are their names? Draw the full structural formula for them.

butan-1-ol

butan-2-ol

Draw the structural formula for 3-methylpentan-2-ol

Name this alcohol

Draw the condensed structural formula for butan-2,3-diol.

Name this alcohol

What is a hydroxyl group?

a hydrogen bonded to an oxygen (-OH)

Which homologous series does the contains a hydroxyl functional group?

Homologous series: alcohol

-OH

Which functional group does the homologous series alcohol contain?

Functional group: hydroxyl

-OH

Other than ketones, which homologous series contains a carbonyl functional group?

Homologous series: aldehyde

What is an aldehyde?

if the carbonyl group is at the end of the carbon skeleton

A O=C-H at the end of the molecule.

》（C=O)H groupd: often consed to CHO.

How do you name an aldehyde?

drop e add al

Suffix: -al

e.g., ethanal (the R group is CH3; the carbon in the C=O is included when counting the number of carbons).

What is a carbonyl group?

Carbon double bonded to an oxygen (C=O)

Which functional group does the homologous series aldehyde contain?

Functional group: carbonyl

What is a ketone?

carbonyl group bonded to 2 carbons

contain a (C=O)R group

--> similar to an aldehyde, (C=O)H

--> carbonyl functional group

How do name a ketone?

Use the suffix "-one"

e.g., propanone (both R groups = CH3; the carbon in the C=O is included in the numbered main chain

Need to specify where the "=O" sits in the main chain (if there is more than option)

Draw the full structural formula for

CH3COCH2CH2CH3. Which homologous series is it apart of? What is the name of the compound?

pentan-2-one

ketone

Write the condensed structural formula for pentan-2-one.

CH3COCH2CH2CH3

Draw the skeletal structure for CH3COCH2CH2CH3. Which homologous series is it apart of? What is the name of the compound?

pentan-3-one

Write the condensed structural formula for pentan-3-one.

CH3COCH2CH2CH3

Draw the full structural formula for . Which homologous series is it apart of? What is the name of the compound?

pentan-3-ol

alcohol

Write the condensed structural formula for pentan-3-ol **** and draw the skeletal structure.

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Draw the skeletal structure of . Which homolgous series is it apart of? What is the name of the compound?

3-methylpentan-2-one

ketone

Write the condensed structural formula for 3-methylpentan-2-one and draw the full structural formula.

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Draw the skeletal structure for **. Which homologous group is it apart of? What is the name of the compound.

3-ethyl-4-methylpentan-2-one

ketone

Do you priorities the functional group or the side chains? Why?

You priorities the functional group over the side chains.