Cat Cracking help plz ><''' (1 Viewer)

[carlytse621]

I know it is a kinda stupid question....but the books confuse me

For the cat cracking, can alkanes with 15 or more carbon atomes per molecule broke into more than TWO molecules????

Like in the conquering chemistry, it says that alkanes are broken into TWO molecules, one an alkane and the other an alkene.

But in the KISS note it says it breaks into some pieces form as alkanes, but others must form as alkenes. In the example it says:

C15H32 - - > C8H18 + C5H10 + C2H4

but in conquering chemistry it says

C15H32 - - > C10H22 + C5H10 THEN
C5H10 - - > C2H4 + C3H6

So is alkane can break down into TWO molecules ONLY???
or actually it can breaks down into more than two?

THX ><

 

[sinophile]

I know it is a kinda stupid question....but the books confuse me

For the cat cracking, can alkanes with 15 or more carbon atomes per molecule broke into more than TWO molecules????

Like in the conquering chemistry, it says that alkanes are broken into TWO molecules, one an alkane and the other an alkene.

But in the KISS note it says it breaks into some pieces form as alkanes, but others must form as alkenes. In the example it says:

C15H32 - - > C8H18 + C5H10 + C2H4

but in conquering chemistry it says

C15H32 - - > C10H22 + C5H10 THEN
C5H10 - - > C2H4 + C3H6

So is alkane can break down into TWO molecules ONLY???
or actually it can breaks down into more than two?

THX ><

Both textbooks are correct. An alkane can be cat cracked into any combination of short alkane+alkene, depending on the exact conditions like temperature and pressure and shit (which you probably dont need to understand)

 

[clintmyster]

Just do what it says in conquering. Otherwise its just overcomplicating things more then you need to. Besides you probably will never have to write an eqn in HSC for catalyctic cracking of hydrocarbons greater then decane (>C10).

 

[sinophile]

Oh shit sorry, I didn't read your question properly. Yes, cat cracking can produce more than two molecules from each alkane, but usually thermal/steam cracking is used for this purpose. You don't really need to understand the specifics of this, just that cat cracking for the purposes of this course produces just an alkane and alkene. I think.

 

[carlytse621]

Yea....I just follow the conquering one to write one alkane and one alkene then THX!!!!