Question

A 30.00 −mL sample of an unknown HClO4 solution requires titration with 23.62 mL of 0.2100 M NaOH to reach the equivalence point. what is the concentration of HClO4?

Answer 1

The concentration of HClO4 is 0.17M

Step-by-step explanation:

Equation of reaction:

HClO4 + NaOH = NaClO4 + H2O

CaVa/CbVb = Na/Nb

From the equation of reaction, number of moles of acid (Na) is 1 and number of moles of base (Nb) is also 1

Va (volume of acid) = 30mL, Cb (concentration of base) = 0.21M, Vb (volume of base) = 23.62mL

CaVa = CbVb (Na/Nb = 1)

Ca (concentration of acid) = CbVb/Va = 0.21×23.62/30 = 0.71M