Chemistry 1010

Fuel Cells and Toothpaste

Fuel Cell

• A fuel cell is a device that converts fuel (Hydrogen Gas) to water

• If the electron transfer portion of the reaction is separated, the electron can be used as electricity

• A fuel cell produces a current

like a battery as long as

fuel is supplied

How a Fuel Cell Works

H+

H+

H+

H+

O2

O2O2

OH2O2

H2

platinumcatalyst

ElectrolyteMembrane

e-e- e-

e- e-

e-

H2

+H22 2

How a Fuel Cell Works

1. Hydrogen (H2) enters one side of the cell and is converted to H+ and electrons by a catalyst

2. The Electrons travel through the wire where they can be used in devices

3. Hydrogen ions (H+) travel through a membrane to the other side of the cell.

4. Oxygen (O2) enters from the opposite side of the cell where

5. The O2, H+, and electrons react to produce water

Fuel Cells Are Used In Space

• Both Gemini and Apollo spacecraft obtained electrical power from hydrogen-oxygen fuel cells

For space applications, fuel cells are better, they produce several times as much energy per equivalent unit of weight

The other advantage of a fuel cell is that the product produced is water which the astronauts use to Drink

Why Don’t We Use Fuel Cells Everywhere??

Fuel Cells require a large volume of hydrogen gas

The fuel cells on the space crafts weighted 500 pounds

This is difficult to put on a car as a fuel tank

So….. Any Ideas to Solve the problem…… What about those nanotubes talked about in the text book????

Use of Nanotubes to store Hydrogen

What is Toothepase Made of???Substance Purpose

Sodium Lauryl Sulfate Detegent

Sodium Monofluorophosphate Decay Prevention

Glycerin Moistener

Water Consistency

Calcium Carbonate Mild Abrasive

Hydrated Silica Mild Abrasive

Xylitol Flavor

Carrageenan Thickener

Oil of Wintergreen Flavor

The Detergent In Toothpaste

This long carbon chain is good at mixing with oils and non-polar scum on the teeth

This polar sulphate end is good at dissolving in water and pulling the carbon chain and scum down the drain

The Workhorse in Toothpaste

• Hydrated Silica

• Calcium Carbonate

Image from: Yahoo Images

These tiny bits of sand grind away at the teeth scouring the plaque and other materials

Preventing Tooth Decay

Sodium Monofluorophosphate

MFP is best known as an ingredient in toothpaste. It is used to protect tooth enamel from attack by bacteria that cause cavities. It was developed by a chemist at Procter and Gamble and was placed in Crest toothpaste in the 1980’s.

Tooth decay is prevented primarily because of the fluorine which inhibits the bacteria’s ability to cause tooth decay

Tooth Paste Flavors

Peppermint

O

spearmint

What do All those lines Mean

Look at all the forms of Hexane (C6H14)