Answer
The mole ratio is 1:1
The molar mass of potassium hydrogen phthalate (C8H5KO4) is 204.22g/mol
The mass of C8H5KO4 is 0.43g
The no of moles of C8H5KO4 = mass/molar mass
No of Moles of C8H5KO4 = 0.000210557242mol
From Mole ratio the no of mole of NaOH that reacted with C8H5KO4 0.000210557242
Therefore, molaroty of NaOH is mole of NaOH/the Volume in L
Molaroty if NaOH = 0.000210557242/0.02411 = 0.08733M