PUTTING THE FUNIN FUNCTIONAL

GROUPS

In-Class Activity

Each station here is devoted to one functional group. Your job is to identify what each functional group is based on the clues given. In some cases the actual material will be present for you to investigate. In others,

you will be given facts and may have to draw the particular group. Answer all the

questions on each page. If you are unclear about anything, please ask the instructor or

one of the lab assistants.

Unknown Number 1This compound was once used as an anaesthetic.

It contains 2 R groups. What does R refer to in organic chemistry?

It is like an alcohol, but the H is replaced by an R.

What is it?

Unknown Number 2These compounds can be very reactive.

Add a few drops of bromine to the liquid in the jar. What do you observe?

Can you make a guess as to what type of bond this contains?

This compound can polymerize, or form a long chain of repeating units. This forms what is considered the most common plastic.

Though these compounds are reactive, they only contain hydrogen and carbon. What are they? (Hint – the general formula for these molecules is CnH2n)

Unknown Number 3These compounds usually have a very unpleasant smell, often resembling garlic. For that reason, PLEASE do not open the jar!

The primary element in this functional group does NOT participate in hydrogen bonding, and the group is an analog of alcohols.

The name for these compounds is a combination of the Greek word for “sulfur” and "alcohol".

What are they?

Draw a tertiary example of this functional group.

Unknown Number 4Test the pH of the material in front of you. Record it below.

Gently waft some of the material toward your nose. What is it?

This functional group is special in that it contains 2 oxygen atoms.

Versions of these with long chains of these are used in making soap. Soaps are usually the sodium salts of such a compound. Can you identify one in the soap in front of you?

What functional group is it?

Unknown Number 5These compounds are known as saturated hydrocarbons.

The cyclic (round) versions of these have the general formula CnH2n. What is the general formula for the acyclic compounds?

Can you draw one of these compounds with a 5-carbon chain?

The jug in front of you contains some dyes dissolved in water. Pour about 20 mL of the mixture in the jug into a clean empty beaker. Now pour some of the mystery compound on top and stir. What do you observe?

What conclusions can you draw about the solubility of the mystery compound?

What conclusions can you draw about the polarity of the mystery compound?

What class of molecules does the mystery compound belong to?

Unknown Number 6Eat a raspberry. The characteristic aroma and taste comes from a chemical whose systematic name is 4-(4-hydroxyphenyl)butan-2-one

Here is a picture of the molecule. What functional groups does it contain? Identify each one.

Which functional group contains a benzene ring?

Unknown Number 7In front of you is a bottle of .

What functional group does it contain?

Use the chart and the picture to determine the electronegativity differences for each bond in the molecule and determine whether the molecule is nonpolar covalent, polar covalent, or ionic.

Unknown Number 8Add 1 mL of Lucas reagent to one of the test tubes. Put the cap on and shake vigorously. Note if an oily layer forms on top, then wait about 3 minutes. Work on the questions below.

This functional group comes in 3 forms depending on the number of carbon atoms bonded to the carbon that is bonded to the functional group. What are the names of these 3 forms?

This particular group is very common as it has many different applications. It can be used as a disinfectant, is common as a fuel both in the lab and in some vehicles, and is produced when some materials ferment.

What is it?

Return to the test that you started at the beginning of this station. This test can be used to tell if this is a primary, secondary, or tertiary compound.

Primary – nothing happens, clear

Secondary – an oily layer forms on top in 3-5 minutes

Tertiary – oily layer forms immediately

Draw a possible structure for this molecule below.

Unknown Number 9These compounds are like carboxylic acids, but one of the oxygens is missing. Draw one of each below and label them.

Smell the cilantro. Does it smell good to you?

Cilantro (also known as coriander) derives its distinctive smell from unsaturated aldehydes. Some people have a genetic predisposition to be extremely sensitive to these chemicals, and, as a result, cannot stand cilantro, saying that it tastes like hairspray or soap. People with out this gene turned on, however, aren’t nearly as sensitive to aldehydes, so it is easier for them to detect the smell of pleasant aromatic compounds also present in cilantro.

Draw and unsaturated aldehyde, then draw a saturated aldehyde and explain the difference.

Unknown Number 10In front of you is an alkyne.

What hybridization has each carbon atom undergone?

Can you draw this molecule including all the orbitals?

Which molecule is more saturated? An alkyne or an alkene and WHY?

Unknown Number 11Waft the gases coming from the test tube. What does it smell like?

This class of compounds is often used in artificial flavorings.

They are formed from a reaction between a carboxylic acid and an alcohol.

Predict the outcomes of each of the combinations below: (Hint – a water molecule is always formed.

Isopropyl alcohol and Pentanoic acid

Ethyl alcohol and Formic acid

Tert-butyl alcohol and ethanoic acid

These reactions do not proceed at a fast enough pace at room temperature, so an acid catalyst is added. Describe what a catalyst is and what is does.

Unknown Number 12 – EXTRA CREDITLook at the jar in front of you. What functional group does it contain?

Pick out a primary, secondary, and tertiary example of this group and paste it to this sheet below. Label each one or you will receive zero credit.

What functional group is a version of this but includes a carbon and an oxygen atom as well?