Remark
HA is an acid that produces only 1 Hydrogen when it breaks down.
The NaOH is a base and a good strong one.
When you do the titration you can be guaranteed that ever mole of NaOH that is consumed represents 100% of what is needed.
So your first step is to find out how many moles of NaOH is needed.
Givens
C = 0.1 mol/L
V = 23.64 mL * [ 1 L / 1000 mL] = 0.02364 L
Formula
C = mol / L
Solution
What you are looking for is the number of mols of NaOH used.
0.1 mol/L = mol / 0.02364 L Multiply both sides by 0.02364
0.1 mol/L * 0.02364 L = mol
mol = 0.002364
Now the number of mols of HA is going to be exactly the same. That's because the titration formula is
HA + NaOH ==> NaA + HOH
==========================
mols = given mass / molar Mass
Molar Mass = given mass / mols
mols = 0.002364 moles
given mass = 0.5632
Molar Mass = ??
Molar Mass = 0.5632 grams / 0.002364
Molar Mass = 238.24 grams
