Chemistry question (1 Viewer)

[pink12]

Why does soft drink left in the sun (eg. lemonade) go flat more quickly than lemonade left in the fridge?

 

[Gavvvvvin]

Is it still in the bottle?

 

[pink12]

yes

 

[cameron0110]

The dissolution of carbon dioxide is exothermic so when the temperature is increased then the equilibrium will move to oppose that change by moving towards the side where heat is absorbed (i.e. carbon dioxide dissolved in the soft drink is released as CO2 gas). No CO2, no bubbles.

 

[pink12]

Thankyou very much

 

[me121]

CO₂(g) <-> CO₂(aq) + heat

Now we know Le Chatellier's principle,

If any chemical system in equilibrium is subjected to a change in pressure, volume, concentration or temperature, then the system will react in the direction to minimise the effect of the change.

So if heat is increased (such as when it is in the sun), the equilibrium moves left (of the first equation) to reduce the heat, so there is more CO2 in gas form. Hence it will go flat.

If it is chilled in the fridge, the equ will shift to the right to produce more heat, producing more dissolved or aqueous CO2.