Volume of acid is 20.30cm3 of hydrochloride was tertired against 25cm3 of 0.1 NaOH solution. Calculate the concentration of the acid in (mole per dm3).And (gram per dm3)

HCl + NaOH ==> NaCl + H2O

moles NaOH = M x L = 0.1 M x 0.025 L = 0.0025
From the equation you see that 1 mol NaOH = 1 mol HCl; therefore, mols NaOH = 0.0025
Then M NaOH = mols/L = 0.0025/0.0203 L =0.123