Hydrocarbons

Question 1

Whats crude oil

Answer 1

Originally a mixture of millions of years of plankton and mud which is then coated with a layer of rock.
With high pressure and temp and no oxgygen it turns inot crude oil.
Crude oil is made of many many different compounds nearly all of which are hydrocarbons, not joined together.
The appearance is dark and smelly

Question 2

What does distilation do for crude oil

Answer 2

Separates it into franctions with different boiling points

Question 3

What is the alkane formula

Answer 3

Cn H2n+2

Question 4

What are alkanes

Answer 4

Saturated Hydrocarbon

Question 5

Methane

Answer 5

1C
4H

Question 6

Ethane

Answer 6

2C
6H

Question 7

Propane

Answer 7

3C
8H

Question 8

Butane

Answer 8

4C
10H

Question 9

the longer the chain…

Answer 9

higher the boiling point, less flamability, thicker and doesnt really turn into gas

Question 10

What are fractions

Answer 10

Hydrocarbons with similar chains/ boiling points so can be used for similar things.

Question 11

Explain the fractional distilation of hydrocarbons

Answer 11

There are these big fat collums and the crude oil is headed near the bottom at a very high temp, the vapour is then released into the collum which is colder at the top. The vapour moves up and condeses at its point, with each fraction then exiting it in its own section. The smallest chains have such low boiling points that they leave out the top as a gas while the biggest chains are thick mixtures that remain at the bottom.

Question 12

Uses of fractions of hydrocarbons

Answer 12

Lowest melting points are good fuels

In the middle it ranges from aircraft, car and engine fuel

The highest melting points are good as roads or roofs

Question 13

What do hydrocarbon fuels do

Answer 13

Release enegy when burnt

Question 14

What is complete combustion

Answer 14

When the carbon and hydrogen atoms in the fuel react with oxgyen and the oxgygen is unlimited it produces co2 and water

Question 15

Whats incomplete combustion

Answer 15

When there isnt unlimited oxygen so the chemical produced is toxic carbon monxide.

Question 16

Whats cracking

Answer 16

long chain hydrocarbons are poor fuels so theyre brocken down by cracking into flamable shorter ones

Question 17

Two types of cracking

Answer 17

Catalystic
Steam

Question 18

Catalystic cracking?

Answer 18

heated until it becomes a gas and then passed over an aluminium oxide catalyst until it splits into an alkene and an alkane

Question 19

Steam cracking?

Answer 19

High temp and mixed with steam

Question 20

What are alkenes

Answer 20

Double coveylent bond between at least 2 carbon atoms
Unsaturated
More reactive than alkane

Question 21

Bromine alkene experiment?

Answer 21

Orange bromine mises with unsaturated/ alkene hydrocarbon to make a colourless mixture

Question 22

whats an isomer

Answer 22

molecule of the same properties, eg hydrogen and carbon, but different arrangments

Question 23

what is organic chemistry about

Answer 23

molecules containing carbon

Question 24

whats a homogulous series

Answer 24

compounds with similar functional properties due to them being isomers

Question 25

how to test for water

Answer 25

it turns blue cobalt chloride pink, gender reveal tease

Question 26

what are feedstocks

Answer 26

any product used for an industrial reaction eg combustion

Question 27

what are petrochemicals

Answer 27

useful products made from hydrocarbons eg petrol and lubricants

Question 28

what kind of reaction is cracking

Answer 28

thermal decomopsition