what volume of 0.115 M HClO4 solution is needed to neutralize 50.00 ml of o.o875 M NaOH?

Answer 1

there are 0.050 * 0.0875 = 0.004375 moles of NaOH.

HClO4 + NaOH -> NaClO4 + H2O

So, you need that many moles of HClO4

0.004375 moles / (0.115 moles/L) = 0.038L
or, 38mL of .115M HClO4 solution