By: Denise Claire Tan Yet Nee
Structure and physical properties of Molecules
Nowadays, there are a lot of alternative fuels which have discovered by human beings in order to replace the depleting non-renewable fossil fuels supply. In fact, organic chemistry has successfully proved that organic compounds can be served substitution of fossil fuel supply.
The structure and physical properties of organic molecules are characteristics that aid them to become useful fuels for human beings. Ethanol, propane and methane are examples of organic compounds which are commonly used as fuels today. What are the structure and physical properties of these compounds that help them to act as excellent alternative fuel sources?
Figure 1 Energy-rich organic molecules (biofuels) are used to fuel cars, planes and ships (Smart Energy Initiative of Southeastern Pennsylvania, 2012)
Alternative Fuel| Structure| Physical Properties|
Ethanol| | * Molar mass: 46.07 g/mol * Appearance: Colourless liquid * Odor: Odorless * Density: 0.789g/cm3 * Melting point:-114℃ * Boiling point:78℃ * Vapor pressure:5.95 kPa (at 20℃) * Polarity: Polar| Propane| | * Molar mass: 44.1 g/mol * Appearance: Colourless gas * Odor: Odorless * Density: 2.0098g/cm3 * Melting point-118℃ * Boiling point:-42℃ * Vapor pressure:853.16 kPa (at 21.1℃) * Polarity: non polar| Methane| | * Molar mass: 16.04 g/mol * Appearance: Colourless gas * Odor: Odorless * Density: 655.6 µg/mL * Melting point:-182℃ * Boiling point:-164- -160 ℃ * Polarity: non polar| (IFA, 2012)
Quantity of energy released during combustion
Other than structure and properties, the amount of energy released through the combustion of the fuels is very vital. A small amount of fuel used to undergo combustion, producing high amount of energy and this is considered as a good fuel. The comparison of energy produced when one kilogram of ethanol, propane...