Is this too long for an answer? (1 Viewer)

[hayabusaboston]

IN a paper I saw, they asked about "changes that occur to cold unopened can of soft drink from fridge when its opened and removed from fridge"
It was worth 5 marks.

There is a three way equilibrium for the solubility of carbon dioxide
C02(g)—C02(aq)
C02(aq)+H20—HC03
HC03*+H20H30*+HC03-
The first equilibrium reaction is an exothermic process in the forward direction. Thus, an unopened, cold, soft drink in the fridge will have its equilibrium point shifted to the right for all three equilibrium reactions, to maintain the exothermic reaction to counter the cooling effect from the fridge (by Le Chatelier’s principle). Thus ultimately causes the concentration of H30* ions to be greater, which gives the drink its favourable acidic taste. Upon removal from fridge, as the drink heats up, the equilibrium shifts to the leftwards endothermic reaction to oppose the heating of the system. Opening the can itself will cause the gaseous carbon dioxide molecules to escape, meaning that to increase their concentration the whole equilibrium shifts to the left even more (le chateliers principle), again decreasing the concentration of hydronium ions and thus lowering the favourable acidic taste. Thus, the progressive heating as well as opening the can work in combination to shift the three way equilibrium leftwards and decrease hydronium ion concentration.

Or maybe its too short... LOL

I think it covers everything doesnt it?

 

[Hoskiies]

Looks fine, if its 5 marks you're aiming to fit in into 10 lines. When writing on paper so I would remove the 'taste' part.

I would also set out mine differently.
Equation
State definition of LCP
↓T → ↑CO2(aq) etc. I wouldn't have to relate back to LCP if I did I'll just write (LCP) instead of the whole name

 

[someth1ng]

Something worth noting is that you got the equilibrium equations weird - there are four equations.

CO2(g) <--> CO2(aq)
CO2(aq)+H2O(l)<-->H2CO3(aq)
H2CO3(aq)+H2O(l) <--> HCO3-(aq)+H3O+(aq)
HCO3-(aq)+H2O(l)<-->CO32-(aq)+H3O+(aq)

Another thing I want to say is to be sure you use the reversible reaction symbol (<-->) or you will lose marks.