Organic Chemistry – Fossil Fuels & Biofuels Flashcards
(26 cards)
What is the main component of natural gas?
Methane (CH₄)
Why is natural gas considered cleaner than other fossil fuels?
It produces less pollution when burned.
Why is methane considered dangerous?
It is flammable and forms explosive mixtures with air.
Why is odorant added to natural gas?
Because methane is odorless; odorant helps detect gas leaks.
What is LNG and why is it used?
Liquefied Natural Gas – methane that is cooled and compressed for safe transport.
What is a use of methane besides fuel?
Making chemicals like methanol and TNT.
What is crude oil?
A mixture of hydrocarbons extracted from underground or under the sea.
Why is crude oil not used directly?
It must be separated into useful products via fractional distillation.
What is fractional distillation?
A process that separates hydrocarbons in crude oil based on their boiling points.
What happens to crude oil before it enters the column?
It is vaporised by heating in a furnace.
Where do substances with higher boiling points condense?
Lower in the column (bottom, hotter).
Where do substances with lower boiling points condense?
Higher in the column (top, cooler).
What happens to boiling point as hydrocarbon size increases?
Boiling point increases.
What happens to viscosity as hydrocarbon size increases?
Viscosity increases (they flow more slowly).
What happens to volatility as hydrocarbon size increases?
Volatility decreases (harder to evaporate).
What happens to flammability as hydrocarbon size increases?
Flammability decreases (harder to ignite).
Why are smaller hydrocarbons more in demand?
They are more flammable and useful as fuels.
Name 3 competing uses of crude oil besides fuel.
Plastics, lubricants, waxes.
Why is crude oil considered non-renewable?
It takes millions of years to form and is used faster than it can be replaced.
List two ways to reduce crude oil demand.
Use public transport; develop alternative energy (e.g., solar, nuclear).
What are biofuels?
Renewable fuels made from plants or animals.
Give one example of a biofuel.
Ethanol (from sugarcane or corn).
How is ethanol produced?
By fermentation of sugar using yeast.
Give the balanced equation for ethanol combustion.
C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O
