in a monoprotic acid , its capable of dissociating 1 H⁺ ion . The base used is NaOH which is capable of giving out 1 OH⁻ ion.
Therefore both base and acid react in a 1:1 molar ratio, that means for each 1 mol of monoprotic acid there is , it requires 1 mol of NaOH to be neutralised.
So at equivalence point the number of acid moles present should react with an equal number of NaOH moles to be neutralised
number of NaOH moles added - concentration x volume
number of NaOH moles - 0.0950 mol/dm³ x 27.4 x 10⁻³ dm³ = 0.00260 mol
since molar ratio of NaOH to Acid is 1:1
number of acid moles present is also - 0.00260 mol
mass of acid added - 0.2140 g
we can find molar mass using following equation
molar mass = mass / number of moles
molar mass = 0.2140 g / 0.00260 mol = 82.3 g/mol
therefore molar mass of monoprotic acid is 82.3 g/mol
