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Chemistry A-Level > Alkanes > Flashcards

Flashcards in Alkanes Deck (21)
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1
Q

What are alkanes

A

Saturated hydrocarbons

2
Q

Are alkanes soluble in water

A

Nope

3
Q

Describe the steps for fractional distillation

A

Heated till most is vaporised, tower which is cooler on top, vapours rise until it condenses into trays, shorter chained hydrocarbons higher up

4
Q

Why is fractional distillation required

A

Petroleum is a mixture containing alkane hydrocarbons of different lengths

5
Q

What is cracking used for

A

Shorter, more useful alkanes are produced.

Alkenes can also be produced

6
Q

Describe thermal cracking

A

High pressure, high temperature, produces a lot of alkenes

7
Q

Describe catalytic cracking

A

Slight pressure, high temperature, zeolite catalyst, produces motor fuels and aromatic hydrocarbons

8
Q

When does incomplete combustion occur

A

Not enough oxygen

9
Q

What is produced with incomplete combustion

A

CO or C

10
Q

How are nitrogen oxides formed in cars

A

This happens in petrol engines due to high temperatures, causing oxygen to react with nitrogen in the air

11
Q

How is sulphuric acid produced

A

Sulfur impurities in crude oil, which is then burnt

12
Q

Problem with water vapour

A

It’s a greenhouse gas

13
Q

How are catalytic convertors used

A

Contains a honeycomb shape with platinum around as catalyst. Reacts CO with NO to produce N2 and CO2

14
Q

How can sulfur be removed from flue gases

A

Calcium oxide, water and oxygen is reacted with SO2 to make calcium sulphate

15
Q

Catalyst for catalytic convertors

A

Platinum or rhodium

16
Q

Carbon length 1 - 4 uses

A

Petroleum gas

17
Q

Carbon 5 - 10 uses

A

Petrol/gasoline

18
Q

Carbon 11 - 20 uses

A

Diesel oil

19
Q

Carbon 21 - 50 uses

A

Lubricating oil

20
Q

Carbon 51 - 70 uses

A

Fuel oil

21
Q

Carbon > 70 uses

A

Bitumen