I don't understand CHM 151 please help :)

Question

A 0.436 g sample of the acid is titrated with 0.185 M NaOH. What is the molar mass of the compound is 13.1 mL of the NaOH solution is required to nutrilize the sample

Answer 1

We need to know more about the acid being tittered with the NaOH. Is it monopritic, diptotic , triprotic? We will assume it is monoprotic (1 titratable H).

Let HA be the acid.

HA + NaOH ==> NaA + H2O

moles NaOH used = 13.1 ml x 1L/1000 ml x 0.185 moles/L = 0.00242 moles NaOH

Since the balanced equation shows us that 1 moles HA equals 1 mole NaOH, we know we have 0.00242 moles of acid, HA.

To find molar mass, we divide the mass by the moles:

molar mass = 0.436 g/0.00242 mols = 180 g/mole