C7- organic chemistry Flashcards
What is crude oil made from?
Plankton buried underwater and compressed over a long time
What is in crude oil?
Hydrocarbons (carbon and hydrogen)
Two types of hydrocarbons?
- Alkanes
- Alkenes
What is the bond in alkanes?
Single covalently bonded carbon atoms surrounded by hydrogen atoms. they are saturated
Alkanes general formula
CnH2n+2
List first 4 alkanes and how many carbon atoms they have
- Methane - 1 carbon
- Ethane - 2 carbons
- Propane - 3 carbons
- Butane - 4 carbons
What needs to happen to the hydrocarbons in crude oil before it is used?
Separated into fractions
How does fractional distillation work?
- They’re evaporated and rise up the fractionating column where they recondense at different heights
- Longer alkanes have higher boiling points due to more energy needed to overcome the stronger intermolecular forces
Equation for complete combustion
fuel + oxygen —-> carbon dioxide + water
Equation for incomplete combustion
fuel + oxygen —-> carbon monoxide + water
General formula for alkenes
CnH2n
Alkene bonds?
Double covalent bond
They are unsaturated
Shorter alkanes v longer alkenes
- Longer alkenes have higher viscosity
- Shorter alkanes are more flammable
What does viscosity mean?
Thickness/gloopiness of something. eg honey has a higher viscosity than water
What can hydrocarbons be used for?
- Solvents
- Lubricants
- Detergents
- Polymers