A 0.2602 g sample of an unknown monoprotic acid requires 12.23 mL of 0.1298 M NaOH solution to reach the end point. what is the molecular mass of the acid?

Answer :-

number of moles of NaOH = molarity * volume in liter 

                                           =0.1298 moles / liter * (12.23/1000) liter  

divide by 1000 to convert ml to liter 

                                          =  0.001587454 moles

same of monoprotic acid so it will give one H + 

and base NaOH  gives only one OH - ions 

and net reaction will  H+   +    OH - ----> H2O 
 

 so moles of acid  = moles of base 

                             = 0.001587454 moles 

          molar mass = mass of substance / number of moles 

                             = 0.2602g/0.001587454 moles 

                             = 163.91 gram / moles 

 Answer :- molar mass of acid is 163.91 grams /mole

A 0.2602 g sample of an unknown monoprotic acid requires 12.23 mL of 0.1298 M NaOH solution to reach the end point. what is the molecular mass of the acid?