A question (2 Viewers)

[kooltrainer]

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]

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]

That's exactly right. Just remember that ph = -log[H₃O⁺] and that the pH of pure water is 7.0 at 25^oC. 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]

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

 

[beentherdunthat]

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

ph7 Is neutral