JAMB - Chemistry (2025 - No. 8)
Calculate the pH of 0.001M KOH solution.
11
14
12
3
คำอธิบาย
Given:
Concentration of OH = [OH\(^-\)] = 0.001 M
At 25\(^0\)C, pH + pOH = 14
Hence, to find pH of KOH, we need to find the pOH first, then substitute the value into the equation above.
Recall, pOH = - Log [OH\(^-\)]
= - Log [0.001]
= - ( - 3)
pOH = 3
pH + pOH = 14
pH + 3 = 14
pH = 14 - 3 = 11
;. pH = 11 - option A