Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Mentos + Coca Cola Light

Posts: 3
Registered: 4-9-2008
Member Is Offline

Mood: No Mood

[*] posted on 29-4-2009 at 12:11
Mentos + Coca Cola Light

Why does Mentos react more violent with Coca Cola Light (also known as Diet Coca-Cola) than normal Coke?

View user's profile Visit user's homepage View All Posts By User
alias Picric-A

Posts: 56
Registered: 6-9-2008
Location: England
Member Is Offline

Mood: vry vry bad mood

[*] posted on 29-4-2009 at 12:21

Mentos react with Coke (generally) becuase it has a highly porous surface and that surace catalyses the breakdown of carbonic acid (carbonated water) to CO2 and H2O.
In real life the decomposition should be the same between diet coke and normal coke. Maybe your coke had been open for a while or was older than the diet coke?
View user's profile View All Posts By User
Hazard to Others

Posts: 120
Registered: 8-10-2008
Member Is Offline

Mood: No Mood

[*] posted on 29-4-2009 at 15:15

Not really sure of this, diet coca cola will react more violently that normal cola. I am not sure of why, but they have some difference into the mix. Maybe it is the Aspartame than can help the reaction, because it is one of the main difference between those two type of cola.
View user's profile View All Posts By User
Biochemicus Energeticus
Thread Moved
29-4-2009 at 15:50
International Hazard

Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline

Mood: Integrated

[*] posted on 29-4-2009 at 18:59

There is not enough aspartame in there to amount to much (even if it were to have any effect). My guess is that the diet drink has a significantly lower viscosity (no sugar). Higher viscosities tend to stabilize dissolved gases in solution (MT limitation). And/or, perhaps, the sugar "fills" some of the surface defects on the mento(s). I think that the pH is normalized between the two, if not, that is certainly a factor.



-Anyone who never made a mistake never tried anything new.
--Albert Einstein
View user's profile View All Posts By User
PHILOU Zrealone
International Hazard

Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline

Mood: Bis-diazo-dinitro-hydroquinonic

[*] posted on 10-5-2009 at 00:38

Following Henry's law of gas dissolution in liquids, the amount of dissolved salts or solutes expels the gas out of the solution!

Adding porrous solids also increases the number of nucleation sites (for nascent bubbles). This effect is used in distillation setups to get a constant bubble flow out of the warmed liquid know the tiny stones

So in fact adding suggar, salt or fine sand to the cola will all end up in a gassing out; but suggar and salt will do it faster because they have two processes (nucleation and dissolution); sand being unsoluble.

I guess that diet cola holding less solute will dissolve faster the mentos pills than normal coke, excess suggar being competitive towards dissolution as Ozone suggested.

PH Z (PHILOU Zrealone)

"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
View user's profile View All Posts By User

  Go To Top