The molecular weight of unknown acid is 33.33 g
HX(aq)+ NaOH(aq) → NaX(aq)+ H₂O(l)
We need to determine the molecular weight of the acid;
Number of moles is given by multiplying molarity and volume of the solution.
Number of moles = Molarity × Volume
= 0.103 M × 0.04365 L
= 0.0045 Moles NaOH
The mole ratio of the acid to NaOH is 1:1
Therefore; the moles of the acid will be 0.0045 moles
Moles of the acid that reacted are 0.0045 moles
Mass of the acid in 0.0045 moles is 0.1500 g
Therefore;
Molecular weight = mass ÷ moles
= 0.1500 g ÷ 0.0045 moles
= 33.33 g/mol
Therefore, the molecular weight of the acid in grams is 33.33 g