After the complete neutralization reaction occurs, excess hydroxide ion is left unreacted the hydroxide ion of the resulting solution, [OH-] is 0.02 M.
The hydroxide ion concentration is the amount in moles of hydroxide ion in a solution.
The hydroxide ion concentration is written as [OH-].
The equation of the reaction is given below:
1 mole of HBr reacts with 1 mole of KOH
Moles of HBr = 40 mL × 0.1 M = 4 mm moles
Moles of KOH = 60 mL × 0.1 M = 6 m moles
Moles of [OH-] = 6 - 4 = 2 m moles
Volume of solution = 100 mL
[tex][OH-] = \dfrac{2m\; moles}{100\; mL} = 0.02 M[/tex]
Thus, the concentration of the hydroxide ion, [OH-] is 0.02 M.
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