#### Answer

The concentration of $NaOH$ is $0.25M$

#### Work Step by Step

1. Find the concentration necessary for an equal number of moles:
12.5ml = 0.0125L
50.0ml = 0.050L
** Since $H_2SO_4$ is a diprotic acid, we have to multiply its concentration by 2 (to get the Hydronium ion concentration in it).
$C_1 * V_1 = V_2 * C_2$
$ (0.500*2)* 0.0125= 0.050 * C_2$
$ 0.0125 = 0.050 * C_2$
$C_2 = 0.25M$