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pivoxa15
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The textbook said if you add dry ice (carbon dioxide) to lemonade or soda water, the pH of the substance (which is already acidic) will become even more acidic. Why?
GCT said:It's actually CO2 + H2O <--> H3O+ + HCO3- (HCO3- is an ampholyte, however, I recall that essential chemistry is that of a base and sometimes employed to neutralize various types of acid solutions).
Carbon acid (H2CO3) is actually not a very weak acid (its Ka is not that small). The pH of carbonic acid is usually pretty low because (i) the solubility product for CO2 in water is low, and (ii) only a small fraction of the dissolved CO2 forms H2CO3. But among the H2CO3 that forms, a relatively significant fraction (nowhere near a majority, but a bigger fraction than HF) dissociates to H+ and (HCO3)- and a very tiny fraction of the (HCO3)- further dissociates into H+ and (CO3)2-.pivoxa15 said:Does the weak cabonic acid form in the process?
So this
H2CO3 + H2O ->HCO3- + H3O+ is more likely
than this
H2CO3 -> CO2 + H2O
What about
CO2 + H2O -> H2CO3 + H2O -> HCO3- + H3O+
This is not what I said. In fact, such a statement actually makes no sense from a chemistry point of view. The correct way to talk about reactions is to discuss the equilibrium conditions and the kinetics that lead to it. At equilibrium, the H2CO3 is as likely to make H2O + CO2 (in a given window of time) as the reverse reaction (by definition).pivoxa15 said:BartDT, I haven't really learned what you wrote but I will post what I have realized from what people like Gokul and GT have said:
It is more likely for H2CO3 to form H2O+CO2 than vice versa
Carbon dioxide dissolves in water to form carbonic acid, which increases the overall acidity of the solution.
When carbon dioxide levels in the atmosphere increase, more of it is absorbed by the ocean, leading to an increase in carbonic acid and a decrease in pH levels, resulting in ocean acidification.
Ocean acidification can have harmful effects on marine life, such as damaging the shells and skeletons of organisms, disrupting their ability to form new ones, and altering the growth and development of some species.
The burning of fossil fuels, deforestation, and other human activities release large amounts of carbon dioxide into the atmosphere, which is then absorbed by the ocean, leading to increased acidity.
While some measures can be taken to reduce carbon dioxide emissions and slow down the process of ocean acidification, the effects are long-lasting and will require significant efforts to reverse.