Alkanes Flashcards

1
Q

What is the general formula of alkanes?

A

CnH2n+2

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2
Q

Give the formula for pentane

A

C5H12

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3
Q

What are some uses of Naptha?

A

Petrochemicals

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4
Q

State some uses of kerosene

A

Jet fuel, petrochemicals

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5
Q

What crude oil fraction is used as diesel fuel?

A

Gas oil

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6
Q

What is heavy fuel oil used as?

A

Ships, power stations

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7
Q

Name the crude oil fraction that is used for candles

A

Wax, grease

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8
Q

Which type of cracking uses a zeolite catalyst?

A

Catalytic cracking

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9
Q

Which type of cracking produces mainly alkenes?

A

Thermal Cracking

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10
Q

Give the conditions required for thermal cracking

A

1000*C
70 atm

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11
Q

State the conditions of catalytic cracking

A

Slight Pressure
500*C

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12
Q

Name the type of hydrocarbon produced in catalytic cracking

A

Aromatic Hydrocarbons

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13
Q

Give 2 advantages of catalytic cracking

A

Faster, cheaper

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14
Q

What is the metal used for catalytic cracking of alkanes?

A

Zeolite

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15
Q

Which type of cracking produces aromatic hydrocarbons?

A

Catalytic cracking

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16
Q

Give 2 products produced during incomplete combustion that aren’t produced in complete combustion

A
  • Particulate carbon
  • Carbon Monoxide
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17
Q

What is needed for complete combustion to occur?

A

Excess of O2

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18
Q

How is carbon monoxide harmful to the human body?

A
  • Binds to haemoglobin on RBC
  • Diminishes O2 supply
19
Q

How can harmful gases be removed from exhaust gases?

A

Using catalytic convertors

20
Q

Give 2 problems with the production of particulate carbon

A
  • Respiratory Problems
  • Build ups in engines prevent them from functioning
21
Q

Are oxides of nitrogen poisonous?

A

Yes, and very toxic

22
Q

How is nitrogen monoxide produced in car engines?

A
  • High pressure and temperature
  • Causes nitrogen and oxygen atoms to react
23
Q

How are unburnt hydrocarbons harmful?

A
  • They react in sunlight to form ground-level ozone
  • Ozone is very harmful
24
Q

Give 3 things that catalytic convertors remove from exhaust gases

A
  • Carbon Monoxide
  • Unburnt hydrocarbons
  • Nitrogen Oxides
25
Q

How is SO2 created?

A

During the burning of sulfur

26
Q

How can sulfur dioxide cause acid rain?

A
  • By dissolving into moisture
  • Sulfuric Acid is created
27
Q

How can sulfur be removed from flue gases?

A
  • By mixing powdered CaO with water and adding to gases
  • Sulfur Dioxide neutralises
  • Harmless Calcium sulfite formed
28
Q

What is a free radical?

A

A particle with an unpaired electron

29
Q

How do free radicals form?

A

When a covalent bond splits equally

30
Q

Why are free radicals so reactive?

A

They have an unpaired electron

31
Q

Give the equation for the synthesis of chloromethane

A

CH4 + Cl2 —> CH3Cl + HCl

32
Q

What occurs in the initiation step of free radical substitution?

A
  • 2 free radicals are produced
  • Covalent bond splits equally
33
Q

Give an example of an initiation step involving Cl2

A

Cl2 –> 2Cl*

34
Q

What occurs in the 2 propagation steps?

A
  • Free radicals are used up and created
35
Q

What occurs in the termination step of free radical substitution?

A
  • Free radicals are used up to make a stable molecule
36
Q

What is a chlorofluorocarbon?

A
  • A halogenoalkane
  • All C atoms are replaced by either F or C atoms
37
Q

How does ozone in the upper atmosphere act as a chemical sunscreen?

A

By absorbing lots of UV from the sun

38
Q

Give two risks of exposure to UV light

A

Sunburn, skin cancer

39
Q

How do CFC’s damage the atmosphere?

A
  • Cl* radicals are formed
  • Radicals act as catalysts and react with O3
40
Q

Describe how the chain reaction between Cl* radicals and ozone occurs

A

Cl* radical is regenerated and goes on to attack another molecule

41
Q

State 3 properties of CFC’s

A

Unreactive, non-flammable and non-toxic

42
Q

Name how CFC’s were used before their problems were discovered

A
  • Coolants in fridges
  • Propellants
  • Fire extinguishers
43
Q

What is the new, safer alternative to CFC’s?

A

HCFC’s, hydrochlorofluorocarbons

44
Q
A