[kenny1999]

if there exists a cup of NaOH and I dilute it with water, will the pH decrease too?

[DevaDevil]

what is pH?

if you dilute it what will happen to the concentrations of Na and OH?

What does this mean for the pH?

[kenny1999]

what is pH?

if you dilute it what will happen to the concentrations of Na and OH?

What does this mean for the pH?

pH is concentration of H+ ion

if I dilute NaOH, the molarity of OH- decreases and the equilibrium of self dissociation of water will shift to the right such that more H+ ion will form. As a result, the pH will increase. Am I right? I am not really sure.

[DevaDevil]

if I dilute NaOH, the molarity of OH- decreases and the equilibrium of self dissociation of water will shift to the right such that more H+ ion will form.

correct

As a result, the pH will increase.

pH = -log [H⁺]

memorize this equation!! So if the concentration of H⁺ increases, what happens to the pH?

[Borek]

if I dilute NaOH, the molarity of OH- decreases and the equilibrium of self dissociation of water will shift to the right such that more H+ ion will form. As a result, the pH will increase. Am I right? I am not really sure.

This is OK for solutions that are not VERY diluted. When you dilute base pH goes up, but there is a limit to how far up it can go.

[DevaDevil]

... When you dilute base pH goes up, ...

when you dilute base, pH goes down (gets lower) you mean I presume?


Point well taken on the dilution, if you have a base, no matter how much water you add, you will not make it acidic (pH<7) - barring carbon dioxide influence.

[kenny1999]

... When you dilute base pH goes up, ...

when you dilute base, pH goes down (gets lower) you mean I presume?


Point well taken on the dilution, if you have a base, no matter how much water you add, you will not make it acidic (pH<7) - barring carbon dioxide influence.

Because of the self dissociation equilibrium of water molecules so if NaOH is diluted to some extent the self dissociation of water dominates so that H+ will remain somehow about 10^(-7) mol dm-3. however, I'd like to know what is the minimum pH that NaOH can reach on continuous dilution?

On the other hand. I really don't understand something

I would like to once ask if Carbonate + Acid => Carbon Dioxide + Water is a kind of neutralization?

According the Bronsted, carbonate receives proton to serve as base while the Acid lose a proton, this is acid-base reaction so it is a neutralization. However, some textbook states that this is NOT a neutralization because neutralization only produces salt and water. So confusing.. what is neutralization??!? Thanks!

[Borek]

... When you dilute base pH goes up, ...

when you dilute base, pH goes down (gets lower) you mean I presume?

Yes, mind slip 

[Borek]

Because of the self dissociation equilibrium of water molecules so if NaOH is diluted to some extent the self dissociation of water dominates so that H+ will remain somehow about 10^(-7) mol dm-3. however, I'd like to know what is the minimum pH that NaOH can reach on continuous dilution?

You wrote it already - seven is the limit.

So confusing.. what is neutralization??!?

To quote wikipedia:

http://en.wikipedia.org/wiki/Neutralization_(chemistry)

Since a variety of definitions of acids and bases exist, a variety of reactions may be considered neutralization reactions.

There is no single answer to your question, which is most likely source of your confusion.