Answer:
[OH-] = 1.8 x 10^-7
Explanation:
pH + pOH = 14 --> 6.93 + pOH = 14 *subtract 6.93 from both sides
pOH = 7.07
-->
10^pH => 10^-6.93 => 1e - 6.93 [H+]
-->
H+ x OH- = 1 x 10^-6.93 *divide H+ from both sides
-->
[OH-] = 1.17 x 10^-7 or 1.8 x 10^-7
