petroleum and alkanes mini test Flashcards Preview

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Flashcards in petroleum and alkanes mini test Deck (15)
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1
Q

are alkanes generally reactive

A

no

2
Q

whats the trend in boiling points with alkanes

A

the longer the carbon chain the higher the boiling point due to stronger van der waals forces between molecules

3
Q

whats the trend with boiling points and branched hydrocarbons

A

the more branches the lower the boiling point due to the molecules having weaker van der waals
forces

4
Q

how is crude oil and natural gas formed

A

the slow decay of
marine biodiversity over millions of years under heat and pressure in the absence of
air

5
Q

what physical property does fractional distillation work by

A

the different boiling points of the hydrocarbons

6
Q

whats the process of fractional distillation

A
  • the crude oil is vaporised
    -the vapour enters the fractioning
    column (hottest at
    bottom - coolest at top)
    -the vapour rises through and different hydrocarbons condense
    at different levels
    -the larger the molecule the lower down it condense
7
Q

whats the trend in physical properties as the carbon chain gets
longer

A

-becomes more viscous
-less volatile
-harder to ignite
-higher boiling
points

8
Q

whats the order of fractions

from the top

A
Fancy    fuel gasses
Geese    gasoline
Nose       naptha
Ketamin  kerosene
Daily        deisel
Rad           residue
9
Q

what are the two kinds of crackig

A

thermal cracking and catalytic cracking

10
Q

what is cracking

A

the breakdown of long chain alkanes

into short chain alkanes

11
Q

describe the conditions

for thermal cracking

A

900 degress celsius
70 atm
produces alkenes

12
Q

describe the coniditions

for catalytic crackig

A

450degrees
1-2 atm
zeolite catalyst
motor fuelsare the product

13
Q

what is reforming

A

turning straight chain hydrocarbons into branches or cyclical so they can burn better and be used as more efficient fuels

14
Q

whats the complete equations for complete combustion

A

CH4 + 2O2 ——>CO2 + 2H2O

15
Q

whats the equation for incomplete combustion

A

2CH4 + 3O2 —-> 2CO + 2H2O