S

Organic Flavor, Part 2

SOL Objective CH. 6

SOL CH. 6 Not really a separate objective. CH =

chemistry, not chapter. This year, we will have an Organic Chemistry

and Biochemistry “flavor” from time to time. Organic = any compound which contains

carbon. Organic compounds usually also contain H and some combination of O, N, S, P, Cl and other elements.

Biochem = study of organic compounds which appear in living things.

Organic Chemistry

All pharmaceuticals (medicines and drugs), plastics, and many products you use and wear everyday are organic compounds.

Some organic chemicals are poisonous (toxic) or carcinogenic (cause cancer potentially), but many are tasty and even vital for life.

Organic Compounds

All organic compounds contain C. However, not all organic compounds

come from nature or living things. But some do. For example, some medicines come

from natural products. Some medicines were created by scientists in a lab.

Natural vs Synthetic

Penicillin was originally isolated from a fungus and found to have antibiotic (kills bacteria) properties. However, the demand for penicillin soon outgrew the ability to get it from fungi and organic chemists figured out how to synthesize penicillin in the lab.

Regardless of whether it is found in nature or synthesized in a lab, all penicillin must have the same properties and be exactly the same in every way.

Important Pharmaceuticals

Think medicines. Pharmaceuticals are any chemical substances used for the diagnosis, cure, treatment or prevention of disease.

Common pharmaceuticals you should know Aspirin Vitamins Insulin

All of the above are organic chemicals, but can be synthesized in the lab or be found in nature.

Inorganic Chemistry

All chemicals which do not contain carbon are inorganic.

Additionally, some compounds which do contain carbon are NOT organic. Examples include: Carbides (metals bonded to carbon) Carbonates Carbon dioxide (CO2)

Note that although water is VITAL to human life, water (H2O) is an inorganic compound, because it doesn’t contain any carbon.

5 Branches of Chemistry Inorganic Chemistry is the study of compounds which

do not contain C. Organic Chemistry is the study of compounds which

DO contain C. Biochemistry is the study of chemical processes

which exist in living organisms. Analytical Chemistry is the study of the separation of

mixtures of compounds and identifying and quantifying those compounds.

Physical Chemistry is the study of physics as it applies to chemical systems at the atomic and molecular level.

-C-C-C-C-C-C-C-C-

Carbon has some unique properties which organic chemistry is based upon.

It can form long chains (or rings) by bonding to other carbons.

Each C forms 4 bonds. In addition to bonding to other carbons, carbon’s unique size as a Period 2 element allows it to form strong bonds with H and O and N and many other elements.

-C-C-C-C-C-C-C-C-

This ability to form long chains allows carbon to bond with itself to produce literally millions of unique compounds.

C can also form double and triple bonds with other C atoms. Additionally, C can form double bonds

with O. C can form triple bonds with N.

Methane = The Simplest Hydrocarbon

Methane boils at 90K. Since room temp = 298K, it is obviously a gas at room temp.

It is also called “natural gas.” It comes out of the gas jets when we do

labs which require a Bunsen burner. The temp of a Bunsen burner flame is

about 1,500 - 2,000°C.

Other Distillation Products from Crude Oil

Gases Ethane, C2H6, used primarily to produce ethene

(also known as ethylene) which is used to produce plastics, such as polyethylene, and is also used force the ripening of fruit.

Propane, C3H8, also known as LP gas (liquified petroleum), can be stored as a liquid at low pressures. Used as fuel for gas grills.

Butane, C4H10, can also be liquified easily at low pressures. Used as fuel in cigarette lighters.

Other Distillation Products

Liquids Gasoline (primarily octane, C8H18, but

contains HC with 5-12 carbons). Kerosene (contains HC with 12-16 carbons).

Used for lamps, stoves and portable heaters. Fuel Oil (contains HC with 15-18 carbons).

Used for heating houses. Also used in diesel engines.

Lubricating Oil (contains HC with 16-20 carbons). Use as motor oil in car engines.

Other Distillation Products

Solids Residue (solids remaining with > 20 carbons

after distillation); used to make asphalt. Paraffin wax (20-40 carbons). Has a variety

of uses, but used to make candles which burn at a very low temp (40-50°C). It is white and odorless and tasteless. James Chadwick used it in experiments to identify the neutron. Liquid paraffin is called mineral oil.

Wax was used to help discover the neutron?

Chadwick in 1932 used α particles (emitted from radioactive Po) and bombarded Be.

Beryllium emitted neutrons during this experiment, but they were hard to detect, because they have no charge.

He put some paraffin in the path of these new particles. They hit the paraffin and knocked out some protons (hydrogen ions).

Wax. Seriously?

Protons have a positive charge and were much easier to detect. Obviously something had to hit it which had enough mass and force to knock the protons loose.

He figured out that the neutron had a little more mass than the proton.

Since it had no charge, the particles didn’t repel when it got close to the positively charged nucleus, and therefore, nothing slowed it down until it collided with the H which it then knocked out of the wax.

Types of HC

Alkanes: only contain C-C single bonds. Known as saturated HC. They are saturated because alkanes have the maximum number of hydrogens bonded to the carbons.

Alkenes: contains at least 1 C=C double bond. Alkynes: contains at least 1 CΞC triple bond. Alkenes and alkynes are unsaturated HC,

because more H could be bonded to the C atoms.

Reactivity of HC

The structure of the molecule helps determine the properties of the compound. All alkanes react the same, but they react differently compared to alkenes or alkynes. Alkynes are MOST reactive. Alkanes are least reactive. That means alkenes are somewhere in

the middle.

Reactivity of HC

From this you can extend your knowledge and predict that triple bonds are more reactive than

double bonds and double bonds are more reactive

than single bonds. We will talk about WHY this is the case in

later units.

Polymers

Large molecule composed of repeating units of simple molecules (called monomers).

Think about Legos. Each block is a monomer. When you hook a bunch of blocks together, you get a large chain (the polymer).

There are two types of polymers (more on this in a later unit). Addition Condensation

Polymers

Natural Polymers Proteins (monomer = amino acids) Starch and Cellulose (monomer = sugar molecules) DNA and RNA (monomer = purine and pyrimidine bases)

Synthetic Polymers Plastics

polyethylene (PE) also known as polythene polyvinylchloride (PVC) polystyrene also known as Styrofoam Sodium polyacrylate (the absorbent polymer in Huggies diapers)

Fibers (nylon, rayon, polyester) Kevlar Teflon (polytetrafluoroethylene)

S

The EndWhat Did you Learn?