Since it goes to completion, we can use: 
Use NaMaVa =NbMbVb 
 
where 
 
Na= moles of H+ in H2SO4 
Ma= molarity of the acid 
Va= volume of the acid 
Nb= moles of OH- in NaOH 
Mb= molarity of the base 
Vb= molarity of the base 
 
 
plug in the numbers 
 
(2 moles of H+) (Volume acid) (10.00mL acid) = (1 mole of OH-) (.248M base) (18.71mL base) 
 
20 V = 4.64 
 
V= .232 M