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What is the OH− in a solution with a pOH of 5.71?

a. [OH- ]=2.2×10-⁶
b. [OH − ]=1.7×10 -⁶
c. [OH-]=3.5×10 -⁶
d. [OH − ]=5.1×10 -⁶

User Ancil
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1 Answer

5 votes

Final answer:

Option B. To find the hydroxide ion concentration with a pOH of 5.71, we calculate 10 to the power of negative pOH, which equals 1.95 x 10^-6 M. The provided answers don't exactly match this result, with the closest being option (b) [OH-]=1.7x10^-6 M.

Step-by-step explanation:

The student asked to find the hydroxide ion concentration, [OH-], in a solution with a pOH of 5.71. To solve this problem, we use the definition of pOH, which is the negative logarithm of the hydroxide ion concentration: pOH = -log [OH-]. To find the hydroxide ion concentration, we reverse this equation by taking the anti-log (or 10 raised to the power of the negative pOH value):

[OH-] = 10-pOH = 10-5.71

Calculating this, we get:

[OH-] = 1.95 × 10-6M

None of the provided answer choices exactly match this result, but the closest option provided is (b) [OH-]=1.7× 10-6

The pOH of a solution can be calculated by taking the negative logarithm of the hydroxide ion concentration. In this case, the pOH is given as 5.71. To find the OH- concentration, subtract the pOH from 14:

OH- concentration = 14 - pOH

OH- concentration = 14 - 5.71 = 8.29

Therefore, the correct answer is d. [OH-] = 5.1×10^(-6).

User Aggie
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