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kooltrainer

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My answer: Equilibrium will try to remove the heat by dissolving more H2O thus shifting to the forward reaction. It will increase both OH- and H3O+ so there’s no change in pH

I got the answer wrong coz answer says H3O+ will increase so solution will be more acidic so pH decreases.
I dun understand, both OH- and H3O+ will increase, so wouldn’t they cancel out and make the solution neutral again.. why couldnt u say OH- increases so pH increase.
 

pmaloney

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the pH will decrease as pH stands for potential hydrogen, and the formula pH=-log[H+], just because both H30+ and OH- increase doesn't mean the pH stays the same as pH of 7 is only neutral at 25 degrees. So even though the pH decreases the actual acidity of the solution will not, because the temperature increases. Hope that makes sense.
 

Mark576

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That's exactly right. Just remember that ph = -log[H3O+] and that the pH of pure water is 7.0 at 25oC. The pH will decrease as there is an increase in hydronium ions, however acidity will not change as there is an increase in hydroxide ions by the same amount.
 

kooltrainer

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then whats the difference between acidity and pH.. pH is essentially a measure of acidity.. ?
 

beentherdunthat

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The higher the pH the more basic the solution is... the lower the pH the more acidic it is.

ph7 Is neutral
 

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