What volume of 0.406 M KOH is required to completely react with 18.50 mL of 0.287 M H2SO4?

Answer 1

H2SO4 + 2KOH ==> K2SO4 + 2H2O

moles H2SO4 initially = M x L = ??
moles KOH (from the equation) = 2x that.
M KOH = moles KOH/L soln.
You have M and moles, solve for L and convert to mL.

Answer 2

1.683