Answer: 1 x 10^-10M
Step-by-step explanation:
Given that,
pOH of solution = ?
pH of solution = 4.00
Recall that pH is the negative logarithm of hydrogen ion concentration in the solution while pOH is the negative logarithm of hydroxide ion concentration in the solution.
Hence, pH + pOH = 14
4.00 + pOH = 14
pOH = 14 - 4.00
pOH = 10
Apply the formula pOH = -log(OH-) to get [OH⁻]
10 = -log(OH-)
(OH-) = Antilog (-10)
(OH-) = 1 x 10^-10M
Thus, 1 x 10^-10M is the [OH⁻] (hydroxide concentration) of that same solution with pH value of 4.00