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Flashcards in C1e Deck (11):
1

What are hydrocarbons?

-any compound that contains carbon and hydrogen only

2

What are alkanes?

-saturated compounds (one single convalent bond)
-will not form polymers
-CnH2n+2

3

What are alkenes

-unsaturated compounds (at least one double bond)
-double bonds can open and join onto things , making alkenes more reactive than alkanes
-CNH2n

4

How are double bonds formed?

-two atoms sharing two pairs of electrons instead of one pair

5

How can you test if a hydrocarbon is an alkene?

-react alkene with bromine water
-shake them together and if the bromine water goes from orange to colourless, it is an alkene
-this is an addition reaction
-bromine adds to the alkene with a double bond to make a colourless dibromo solution
-bromine water has decolourised

6

What are the fractions of crude oil?

-LPG (liquefied petroleum gas)
-petrol
-napatha
-kerosene (paraffin)
-diesel
-oil (fuel oil, heating oil, lubricating oil)
-bitumen
each fraction contains a mixture of hydrocarbon with similar boiling points

7

How is crude oil separated into different hydrocarbon fractions?

-factional distillation
1-oil is heated until mostly gas
2-gases enter the bottom of the factional distillation column (has a temperature gradient)
3-bitumen drains off at the bottom as it is a liquid at the hottest bottom (hot)
-the longer the hydrocarbon the higher the boiling point, turn into liquids and drain out of the column earlier on, near the bottom
-the shorter the hydrocarbon the lower the boiling point, liquefy and drain out nearer the top later on, where it is cooler

8

How do hydrocarbon properties change as the size increases?

-boiling point increases
-less flammable
-more viscous (doesn't flow as easily)
-less volatile

9

What is crude oil?

-formed from fossils of plants and animals and turn to crude oil by high temperature and pressure
-mixture of lots of different hydrocarbons

10

What important types of bonds are in crude oil?

-strong covalent bonds between carbons and hydrogen within each hydrocarbon molecule
-intermolecular forces of attraction between different hydrocarbon molecules

11

Why do the properties of crude oil change?

-the longer the hydrocarbon, the stronger the intermolecular forces, the higher the boiling and melting point