Question

(39) What is the concentration of hydroxide ions in a solution given that the concentration of hydronium ions is 2.31 x 104 M? (a) 4.33 x 10-10 M (b) 4.33 x 10-11 M (c) 2.31 x 10-18 M. (d) 1.01 x 105 M

Answer 1

For aqueous solutions, the following relationship  is always true:

Kw = [H3O+10H

And we know that the value of

Putting the value of we get,

Ky and [H30+

$10^{-14}=[2.31*10^{-4}][OH^-]$

therefore, we can find the

он-

$[OH^-]=\frac{10^{-14}}{2.31*10^{-4}}$

Therefore, The concentration of hydroxide ions comes out to be .
Option (B)

Important points:

• Remember the formula
  Kw = [H3O+10H
  
• $pH+pOH=14$ in the case when pH is given.
• $pH=-log[H_{3}O^+]$
• $pOH=-log[OH^-]$