1. In pure water, what is the concentration of H3O+ and OH- ions? What is the pH?
2. What is the pH of a solution with [H3O+] = 1 x 10^-6 M? is it acidic or basic?
3. The pH of a solution devreases from 9 to 7. How does the concentration of [H3O+] ions change?
4. In a solution, [OH-] = 3.4 x 10^-10 M. What is the pH of the soltuioin? Is it acidic or basic?
2007-06-15 15:51:52 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
pH is the
"power" of "Hydronium ion concentration"
The hydronium is H3O+. When you measure pH, you are measuring the exponent on the number 10 of the concentration of that ion.
pH = the negative of the base 10 logarithm of the concentration of hydronium
So if [H3O+] is 10^-4, the base 10 logarithm of this is -4, and the opposite of this is 4. Therefore, the pH is 4.
A pH of 7 is normal for pure water at 25 degrees Celsius. If the pH is greater than 7, the solution is basic. Less than 7, and it's acidic.
2007-06-15 15:59:34 · answer #1 · answered by lithiumdeuteride 7 · 0⤊ 0⤋
In pure water, teh H3O+ and the OH- concetrations are equal at 1x10E-7 mol/L
To calculate the other pH questions, take the negative log of the H3O+ concentration. If it is below 7, it is acidic, above 7 it is basic.
For your last question, calculate the pOH in a similar fashion. Then subtract it from 14 to get the pH.
2007-06-15 15:57:21 · answer #2 · answered by reb1240 7 · 0⤊ 0⤋