Question

What is the [oh−] of a solution with ph 5.75

Answer 1

[ H₃O⁺] = 10 ^- pH

[ H₃O⁺] = 10 ^ (- 5.75 )

[H₃O⁺] = 1.778x10⁻⁶ M

Kw = [ H₃O⁺] x [ OH⁻]

1x10⁻¹⁴ = 1.778x10⁻⁶ x [OH⁻]

[OH⁻] = 1x10⁻¹⁴ / 1.778x10⁻⁶

[OH⁻] = 5.62x10⁻⁹ M

hope this helps!

Answer 2

Explanation:

pH means potential of hydrogen and it is defined as the measure of concentration of hydrogen ions in a solution.

Mathematically,         pH = $-log[H^{+}]$

Also, it is known that relationship between pH and pOH is as follows.

                          pH + pOH = 14

or                        pOH = 14 - pH

Therefore, putting the value of pH in the above relationship as follows.

                         pOH = 14 - pH

                                  = 14 - 5.75

                                  = 8.25

Hence, pOH = $-log [OH^{-}]$

    or,              $[OH^{-}]$ = antilog (-8.25)

                                                  = $5.62 \times 10^{-9}$    

Thus, we can conclude that the [oh−] of a solution with ph 5.75 is $5.62 \times 10^{-9}$.