What is the (OH-) when pH = 4.25

Remember this.

pH + pOH = pKw = 14
You know pKw and pH, solve for pOH. Then
pOH = -log(OH^-), substitute and solve for OH^-.

im confused, is the answer 1.77827941x10^-10 or 5623413252????

It's 1.78E-10.

Why are you confused.
14-4.25 = 9.75 = pOH
Then pH = -log(OH^-)
-9.75 = log OH^-
OH^- = 1.78E-10

OR

OH^- = 10^-pOH
OH^- = 1.78E-10

To determine the concentration of hydroxide ions (OH-) in a solution when given the pH, you can use the formula for calculating the concentration of hydroxide ions in an aqueous solution:

OH- concentration = 10^(-pOH)

Since pH + pOH = 14, you can find the pOH value by subtracting the pH from 14:

pOH = 14 - pH

In this case, pH is given as 4.25, so:

pOH = 14 - 4.25 = 9.75

Now, plug the pOH value into the formula to find the OH- concentration:

OH- concentration = 10^(-pOH) = 10^(-9.75)

Using a calculator, you can solve this expression:

OH- concentration = 1.78 x 10^(-10)

Therefore, when the pH is 4.25, the concentration of hydroxide ions (OH-) is approximately 1.78 x 10^(-10) M.