We need (i) a stroichiometric equation:
$H_2SO_4(aq) + 2NH_3(aq) rarr 2NH_4^+ + SO_4^(2-)$
At the 2nd equivalence point, the solution will stoichiometric in $"ammonium sulfate"$. An appropriate indicator must be used.
And (ii) a calculation,
$[H_2SO_4]=1/2xx(32.8xx10^-3*Lxx0.116*mol*L^-1)/(25.0xx10^-3*L)$
$=??*mol*L^-1$
Why did we use a $1/2$ factor in the calculation?