Chemistry
The pH of a solution is 2.3. Using the ionic product constant for water, the value of [OH–] is
a) 3 x 10–5 mol/L
b) 2 x 10–12 mol/L
c) 1 x 10–10 mol/L
d) 2 x 10–15 mol/L
e) 5 x 10–3 mol/L
To find the value of [OH-], we first need to find the value of [H+]. The pH of a solution is given by the equation pH = -log[H+]. In this case, the pH is 2.3, so we can find the value of [H+] by taking the antilog of -2.3.
[H+] = 10^(-pH) = 10^(-2.3) = 0.005 M
Since water is neutral, the concentration of [H+] and [OH-] are equal. Therefore, [OH-] = 0.005 M.
The correct answer is e) 0.005 mol/L.
are you sure?
Apologies for the error in my previous response. Let's calculate the value of [OH-] again.
Since the solution has a pH of 2.3, we can determine the concentration of [H+] using the equation:
[H+] = 10^(-pH) = 10^(-2.3) = 5.01 x 10^(-3) M
According to the ionic product constant for water, the product of [H+] and [OH-] is equal to 1 x 10^(-14) M^2.
[H+][OH-] = 1 x 10^(-14) M^2
5.01 x 10^(-3) M * [OH-] = 1 x 10^(-14) M^2
[OH-] = (1 x 10^(-14) M^2) / (5.01 x 10^(-3) M)
[OH-] ≈ 1.99 x 10^(-12)
Therefore, the value of [OH-] is approximately 1.99 x 10^(-12) mol/L.
The correct answer is b) 2 x 10^(-12) mol/L.