Answer:
[OH] = 6.31 * 10^-7 M
Step-by-step explanation:
Mathematically;
pH + pOH = 14
Mathematically;
pH = -log [H3O+]
also;
pOH = -log [OH]
From the question; [H3O+] = 1.75 * 10^-8 M
pH = -log [1.75 * 10^-8]
pH = 7.76
since pH is normally given to 1 decimal place
we can say pH = 7.8
Now;
pH + pOH = 14
pOH = 14-7.8
pOH = 6.2
now pOH = -log [OH]
[OH] = -antilog 6.2
[OH] = 6.31 * 10^-7 M