What is the concentration of 10.00 mL of HBr if it takes 5mL of a 0.253M LiOH solution to neutralize it?

The chemical reaction would be:

HBr + LiOH = LiBr + H2O

We are given the concentration of the other reactant. We use these given values and the reaction to relate to moles of HBr needed. We do as follows:

0.253 mol / L (.005 L) (1 mol HBr / 1 mol LiOH) = 0.0013 mol HBr

Molarity = 0.0013 / 0.01 = 0.13 M