S30 Unit B: Problems with Organic Molecules

4/12/17

There are organic molecules (chemicals primarily made up of carbon, hydrogen and a few other elements tossed in) all around you. Previously, we learned about three functional groups common to organic chemicals. Today, we look at some more specific examples. You will need to know some common examples for your exams.

1. Halogenated Hydrocarbons

- are commonly called "CFCs" (______-______-carbons)

- Some common examples include:

What's Cool About Fridges...

Refrigeration/air conditioning/freezers all rely on ______, which traditionally were CFCs like ______(brand name). These chemicals were fire-retardant, non-toxic and very good at condensing and absorbing heat.

However, they also lead to high levels of ______depletion, and were largely banned under the 1987 Montreal Protocol and the 1992 Kyoto Protocol.

Today, chemicals that do not react with ozone are used, such as ______.

Ozone Depletion

When CFCs enter the atmosphere, they react ozone (______) molecules. Ozone forms a protective barrier against UV radiation. The depletion of the ozone layer has lead to higher incidence of ______due to _____ radiation.

International efforts to reduce CFCs released into the atmosphere has meant that the depletion is slowing, and it is thought that by the mid to late 21st century, the ozone layer should start to recover (partial recovery was reported in 2016)

ex) The common replacement to Freon is 1,1,1,2 tetrafluroethane. Draw the chemical structure of this compound.

PCBs – Poly Chlorinated Biphenyls

-were produced up until the 1960s and were used in a wide range of applications such as ______, coolants, ______oils, fire retardants, household ______, cement, caulking, wood floor finishes, and more

-in the 1920s these chemicals were discovered to be hazardous to humans, causing everything from rashes to ocular ______to irregular ______cycles to cancer.

-PCBs have been banned for production, but remain in the water systems of many regions as they are very chemically stable: they do not break down easily or degrade.

-because of this, PCBs fall into a particularly insidious category of chemicals:

POPs: ______

-pollutants that don't ______easily in the environment

POPs bioaccumulate through the ecosystem, particularly in the fats of animals. This can be a particular concern for ______peoples who make animal fats, such as beluga skin or whale blubber, a main part of their diet.

2. Alcohols - aside from human consumption, common uses of alcohols include:

Ethanol can be used for ______or in hand sanitizer.

Methanol is used in making cleaning supplies and in ______.

The production of ethanol for use as a gasoline additive (most vehicles can run off a blend up to 15% ethanol) has become a political issue.

Pros:

- ethanol releases ______carbon dioxide when burned, making it a good alternative to gasoline in vehicles

- ethanol can be produced from ______resources (plants)

Cons:

- ethanol releases ______energy when burned, leading to ______fuel economy

- land traditionally used for growing food crops now are used for ethanol crops (corn). This has lead to increased food and livestock prices

3. Carboxylic acids are found in:

ex) Circle the carboxylic acid group on aspirin (left) and citric acid (right).

Omega-3 Fatty acids, compounds which we learned could lower your "______cholesterol" (LDL) back in Unit A, are also carboxylic acids.

4. Esters show up in many everyday applications, such as:

Dioxins and Furans

These two chemical families contain toxic compounds that are found in very ______amounts in the environment. As a result, they are also found in some _____ in Canada.

Dioxins and Furans sources include:

Dioxins and Furans can have a number of health effects, including:

- ______disorders

- ______problems

- immune and ______system impairment

- certain types of ______

The impact on humans depends on:

- the way the exposure occurs (through food, ______, air, etc)

- the amount of daily ______

The Dose Makes the Poison

Dioxins and Furans, like most toxins, are harmful when exposure reaches a certain level.

Dioxins and furans bioaccumulate in fats in animals: as a result, Health Canada suggests individuals wishing to minimize their risk to these toxins avoid fatty foods.

Benzene- a cyclic hydrocarbon of six carbons

The benzene molecule is used for many industrial applications, including the production of:

- ______

- lubricants

- dyes

- drugs

- ______

Benzene is also present in:

- ______

Health effects of benzene exposure include:

- bone cancer

- ______

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