How do you find the molar mass of an unknown acid if you know the weight of the sample (in grams) and the volume of the solution (250mL)?

My base is NaOH. I also know the amount used of each solution (Acid and Base) during the titration (In mL).

I am trying to find the molarity of the acid but I don't know the molar mass of the unknown acid to finish my problem.

Can you help?

Thank you.

Did you do a full titration with recording the titration curve as well?

I don't know what a titration curve is. I recorded all my measurements regarding the acid and the base and their levels.

A chemist dissolves 0.9g of an unknown monoprotic (one acidic H) acid in water. The chemist finds that 14.6mL of 0.426M NaOH are required to neutralize the acid.
How many grams of acid are present?
There are 0.9g present.

How many moles of base are required to reach the equivalence point?
mol=(M)(L)
mol=(0.426mol/L)(0.0146L)
mol=0.006219mol
Therefore, 6.219 x 10-3 mol of NaOH are required.

How many moles of acid are present initially?
mol Acid = mol Base = 0.006219mol
Therefore, 6.219 x 10-3 mol of acid were present before the titration.

What is the molar mass of the acid?
m.m.= g/mol
m.m.= (0.9g)/(0.006219mol)
m.m.= 144.72g/mol

What is the chemical formula and name of this acid?
The formula is HBrO4, and the name is perbromic acid.