16. The $[\; H$₃O ] at $25oC$, in a 0.00040 M solution of KOH (a strong electrolyte) is:

a) $2.5\; x\; 10-11$
b) $4.0\; x\; 10-4$
c) $2.5\; x\; 10-10$
d) $2.5\; x\; 10-3$

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