Temperature and acidity

[wannabedocta]

How does temperature affect acidity??

For the auto ionization of pure water (endothermic), the hydronium and hydroxide ions are the product. What effect does increasing temperature have on the pH? The answer says that pH would decrease because [H+] increases.

I understand temperature increases Keq of water so more of the pure water molecules would dissociate. Why is it that more H+ ions than OH- are formed?

---

Members don't see this ad.

 

[coffeebythelake]

How does temperature affect acidity??

For the auto ionization of pure water (endothermic), the hydronium and hydroxide ions are the product. What effect does increasing temperature have on the pH? The answer says that pH would decrease because [H+] increases.

I understand temperature increases Keq of water so more of the pure water molecules would dissociate. Why is it that more H+ ions than OH- are formed?

In pure water, there is an equal number of H+ and OH- regardless of temperature. The auto ionization reaction is 2H20 <--> H30+ + OH-

The reason why pH becomes smaller is due to the definition of pH = -log[H+].

Note that the pOH = -log[OH-] also becomes smaller.

 

[wannabedocta]

In pure water, there is an equal number of H+ and OH- regardless of temperature. The auto ionization reaction is 2H20 <--> H30+ + OH-

The reason why pH becomes smaller is due to the definition of pH = -log[H+].

Note that the pOH = -log[OH-] also becomes smaller.

ahhhhhhh!!!!! i got it. Thanks a lot!

 

[Chargers]

In pure water, there is an equal number of H+ and OH- regardless of temperature. The auto ionization reaction is 2H20 <--> H30+ + OH-

The reason why pH becomes smaller is due to the definition of pH = -log[H+].

Note that the pOH = -log[OH-] also becomes smaller.

wait a minute, isn't it true that pH + pOH = 14? If both pH and pOH are decreasing, that means the previous equation becomes false. How's that possible?

 

[coffeebythelake]

wait a minute, isn't it true that pH + pOH = 14? If both pH and pOH are decreasing, that means the previous equation becomes false. How's that possible?

pH + pOH = 14 only at standard temperature. It can change.

 

[Chargers]

pH + pOH = 14 only at standard temperature. It can change.

right on

 

[wannabedocta]

i wish i was as smart as eikenhein....