Calculate the concentration of OH− and the pH value of an aqueous solution in which [H3O+
] is 0.014
M at 25°C. Is this solution acidic, basic or neutral?
To calculate the concentration of OH- and the pH value of the solution, we can use the equation for the ion product of water:
Kw = [H3O+][OH-]
At 25°C, the value of Kw is 1.0 x 10^-14. Given that the concentration of H3O+ ([H3O+]) is 0.014 M, we can rearrange the equation to solve for [OH-].
Using the equation:
Kw = [H3O+][OH-]
we can substitute the given values:
1.0 x 10^-14 = (0.014 M)([OH-])
Rearranging the equation to isolate [OH-]:
[OH-] = (1.0 x 10^-14) / (0.014 M)
[OH-] = 7.14 x 10^-13 M
Now, to find the pH value, we can use the equation:
pH = -log[H3O+]
Substituting the given value of [H3O+] into the equation:
pH = -log(0.014)
pH ≈ 1.85
Finally, to determine the acidity or basicity of the solution, we can consider the pH value.
A pH value below 7 is acidic, a pH value of 7 is neutral, and a pH value above 7 is basic. In this case, since the pH value is approximately 1.85, the solution is acidic.