2.5 L 1M Naoh with 3 L 0.5M NaOH. Intially, Number of moles in 2.5 L, 1MNaOH=2.5×1=2.5 moles Number of moles in 3 L,0.5MNaOH =3×0.5=1.5 moles. ⇒ Total number of moles in final mixture =2.5+1.5=4.0 moles . The total volume of solution =2.5+3=5.5 L ⇒ Molarity of final solution =5.54=0.728M