At a certain temperature, the pH of a neutral solution is 7.77. What is the value of Kw at that temperature?
If the pH = 7.77, the pOH must be 7.77 so pKw must be 1.77 + 7.77 = ??
At a certain temperature, the pH of a neutral solution is 7.77. In a neutral solution, the concentration of both H+ ions and OH- ions is equal.
The pH is defined as the negative logarithm (base 10) of the concentration of H+ ions, and in a neutral solution, the concentration of H+ ions is 10^-7.77 M.
Since the concentration of H+ ions is equal to the concentration of OH- ions in a neutral solution, the concentration of OH- ions is also 10^-7.77 M.
The product of the concentration of H+ ions and OH- ions in any aqueous solution is equal to the ion product of water (Kw), which is a constant value at a given temperature.
Therefore, we can calculate the value of Kw at the given temperature by multiplying the concentration of H+ ions and OH- ions:
Kw = [H+] * [OH-] = (10^-7.77 M) * (10^-7.77 M) = 10^-15.54
Therefore, the value of Kw at that temperature is 10^-15.54.
To determine the value of Kw (the ion product of water) at a certain temperature, you need to know the pH of a neutral solution at that temperature.
The ion product of water, Kw, is defined as the equilibrium constant for the self-ionization of water:
Kw = [H3O+][OH-]
In a neutral solution, the concentration of H3O+ (hydronium ion) is equal to the concentration of OH- (hydroxide ion). Therefore, in a neutral solution:
[H3O+] = [OH-]
Since the pH of a neutral solution is 7.77, you can convert this pH value back to the concentration of H3O+ or OH- using the formula:
pH = -log[H3O+]
Substituting the given pH value:
7.77 = -log[H3O+]
To solve for [H3O+], you need to take the antilog of both sides:
[H3O+] = 10^(-pH)
[H3O+] = 10^(-7.77)
Now that you know the concentration of H3O+ (which is equal to the concentration of OH- in a neutral solution), you can use this value to calculate the value of Kw at that temperature.
Kw = [H3O+][OH-]
Kw = (10^(-7.77))(10^(-7.77))
Kw = 10^(-7.77 - 7.77)
Kw = 10^(-15.54)
Therefore, the value of Kw at that temperature is approximately 10^(-15.54).