[umegard]

If I were to remove H+ ions from my destilled water, what would happen to the pH?

I other words, can you construct an acid/base that is just water with a non neutral pH?

[Dan]

If you remove the H⁺, you have to replace it with another cation, and then you don't have pure water. Eg. Replace H⁺ with Na⁺ and you have a sodium hydroxide solution.

[DevaDevil]

1 - there is no such thing as 100% pure water, even triply distilled water, or the purest Millipore water has some ions / contaminants.

2 - Kw (water equilibrium (heard of it?, then apply Le Chatelier's priciple; remove the H+ and there will be made more of it from OH-, as well as water will split back up in H+ and OH- to resupply the concentration of these 2 ions)

so answer is very easily: NO


To change pH add acid or base, like sodium as Dan said

[umegard]

Thanks for your answers!

[Mitch]

If you could selectively remove H⁺ from water the pH would go up obviously enough. But, the more interesting observation would be to see what a liquid with excess negative charge that is electrically isolated from its environment would do if left to its own devices.

[maakii]

Kw is also dependent on temperature, if temperature is increased, Kw will also increase, and there are more OH- and H+ ions. Thus, pH will change.

However i am not sure if it increases or decreases, can anyone help me with this?

[Borek]

In general Kw increases with temperature, pH of pure water goes down with temperature. I don't remember exact details and I can't locate them right now. I think CRC handbook contains table of Kw vs T.

[Ψ×Ψ]

Kw is also dependent on temperature, if temperature is increased, Kw will also increase, and there are more OH- and H+ ions. Thus, pH will change.

However i am not sure if it increases or decreases, can anyone help me with this?

Excellent point!  I'd completely forgotten about that!

[maakii]

Thanks!

Hey everyone i found this,

T (°C)   Kw (mol2 dm-6)   pH
0   0.114 x 10-14   7.47
10   0.293 x 10-14   7.27
20   0.681 x 10-14   7.08
25   1.008 x 10-14   7.00
30   1.471 x 10-14   6.92
40   2.916 x 10-14   6.77
50   5.476 x 10-14   6.63
100   51.3 x 10-14   6.14

So in summary pH goes down as temperature increases, but the solution is not considered more acidic, as the number of OH- ions increases as well. The new pH value of pure water at the new temperature is now considered the new "neutral value".

To read up more go here : http://www.chemguide.co.uk/physical/acidbaseeqia/kw.html