If 25.21 ml of NaOH solution is required to react completely with 0.550 g KHP, what is the molarity of the NaOH solution? Answer MUST be in Mol NaOH/L solution. Do not put in scientific notation.

[NaOH] = 0.107M

Explanation:

25.21ml of NaOH(aq) soln + 0.550g KHPh => NaKPh + H₂O

The reaction is 1 to 1 NaOH to KHPh => moles NaOH neutralized = moles KHPh used. (KHPh => Potassium Hydrogen Phthalate f.wt. = 204.22 g/mol)

moles KHPh = 0.550g / 204.22g·mol⁻¹ = 0.0027 mole

moles NaOH neutralized = moles KHPh used = 0.0027 mole NaOH in 25.21ml aqueous solution ...

Molar concentration of NaOH solution = moles NaOH/Liters solution = 0.0027mol NaOH/0.0251L = 0.107M NaOH solution.