In a titration, 3.2 g of an acid (HX) requires
36.7 mL of 0.78 M NaOH(aq) for complete
reaction. What is the molar mass of the acid?
Answer in units of g/mol.
HX + NaOH ===> NaX + H2O
millimols NaOH = mL x M = 36.7 mL x 0.78 M = 28.6
28.6 mmols NaOH x (1 mol HX/1 mol NaOH) = 28.6 mmols HX = 0.0286 moles.
Then mols = g/molar mass
0.0286 = 3.2/molar mass
molar mass = 3.2/0.0286 = ?