Question

The reaction of perchloric acid (HClO4) with lithium hydroxide (LiOH) is described by the equation: HClO4 + LiOH → LiClO4 + H2O Suppose 100 mL of perchloric acid is neutralized by exactly 46.9 mL of 0.75 M lithium hydroxide. What is the concentration of the perchloric acid?

Answer 1

[HClO₄] = 0.35 M

Step-by-step explanation:

Neutralization reaction is:

HClO₄ + LiOH → LiClO₄ + H₂O

In this case, we have a titration between a weak acid and a strong base.

In chemistry it is also called an acid base equilibrium.

HClO₄ + H₂O ⇄ ClO₄⁻ + H₃O⁺ Ka

The weak acid is firstly neutralized by the strong base, in order to have a buffer solution before the equivalence point.

When we reach the equivalence point, mmoles of acid = mmoles of base and there is a formula to determine it so:

M acid . Volume of acid = M base . Volume of base

M acid . 100 mL = 0.75 M . 46.9 mL

M acid = (0.75 M . 46.9 mL) / 100 mL → 0.35 M