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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: cuongt on June 13, 2006, 07:09:59 AM

Title: Fizzy Drinks and Le chatelier's priciple
Post by: cuongt on June 13, 2006, 07:09:59 AM

i dont know where to start with this question

sealed bottles of "fizzy" drinks such as coke and sparkling wines contain carbon dioxide gas in equilbrium with disolved carbon dioxide:
CO2(g) <----> CO2(aq)    the forward reaction is exothermic
a) use Le chatlier's principle to explain why bubbles appear when bottle are opened
b) why are drinks usually cooled before they are carbonated.

ty in advanced   ; :D

Title: Re: Le chatelier's priciple
Post by: Dan on June 13, 2006, 07:28:11 AM

a) think about pressure
b) think this is about the enthalpy of solvation of carbon dioxide

Title: Re: Fizzy Drinks and Le chatelier's priciple
Post by: Donaldson Tan on June 14, 2006, 07:15:08 AM

When you open up the bottle, the pressure inside drops. Le Chatelier's Principle (LCP) would therefore require the chemical system to respond in such a way that increases the pressure. This means the position of the equilibrium shifts to the right, to produce carbon dioxide gas, and hence the fizz...

According to LCP, which reaction is favoured by low temperature - endothermic or exothermic?

Title: Re: Fizzy Drinks and Le chatelier's priciple
Post by: Morphic flip on June 14, 2006, 04:29:48 PM

Quote

CO2(g) <----> CO2(aq)    the forward reaction is exothermic

Quote

why are drinks usually cooled before they are carbonated.

You`ve unknowingly answered the question.