8.4 pH Flashcards
(12 cards)
What is the equation for pH?
-log10[H+(aq)]
What are the units for pH?
pH has no units.
What is the equation for finding the concentration of hydrogen ions?
[H+(aq)] = 10^(-pH)
What happens to the concentration of H+ ions when the pH increases by one unit?
A 10 fold decrease in the H+ concentration is required to increase the pH by one unit - every time a solution of strong acid is diluted by a factor of 10 the pH goes up by 1 unit.
How does water dissociate?
H2O (l) H+ (aq) + OH- (aq)
What is the equilibrium constant for the dislocation of water?
Kw = [H+(aq)][OH-(aq)]
Why is the concentration of water not included in the expression for Kw?
Because it is the solvent and its concentration is essentially constant.
What is Kw known as and what is its value?
The ionic products constant for water and has a value of 1.0x10^-14 at 25 degrees Celsius.
In any aqueous solution at 25 degrees celsius what is equal to 1.0x10^-14?
The product of H+ concentration and OH- concentration is 1.0x10^-14
When is the only time [H+] equals [OH-]?
In a neutral solution or in pure water.
What is the concentration of H+ ions compared to OH- in an acidic solution?
[H+] > [OH-]
What is the concentration of H+ ions compared to OH- in an alkaline solution?
[OH-] > [H+]
