What reaction occurs when 35.8mL of 0.00194M HClO4 are mixed with 20.0 mL of 0.00356MNaOH? (Assume volumes are additive.)?

A) Write a "Net Ionic" Equation for the species

B) What is the concentration of each (molecule or ion!) present in solution after the mixture has reacted?

C) Finally, determine the pH and pOH of the solution?

1 Answer
May 5, 2018

An acid-base reaction. Consider,

#HClO_4 + OH^(-) rightleftharpoons H_2O + ClO_4^(-)#

puu.sh

From the preceding data, we need to calculate the molarity of each species at equilibrium by dividing the moles present by the total volume of the solution.

#[OH^-] approx 3.05*10^-5"M"#
#[ClO^-] approx 1.25*10^-3"M"#

For the last part of your question, we need to consider how the acid, #HClO_4# dissociates. It is a strong acid, so we assume it completely dissociates. Thus,

#"p"H = -log[HClO_4]_"i" approx 2.90#

and by extension,

#"p"OH = 14 - "p"H = 11.10#