Experiment 25_Determination of Dissociation Constant of a Weak Acid.pdf

Student Name: Mina Nakhla
Experiment Name: Experiment 25:Determination of Dissociation Constant of a Weak Acid
Submission Date: 03-029-2021
Lab Partners: Micheal and Anathony
Report Element Points Earned Maximum Value
Abstract __________ 10
Introduction __________ 15
Experimental __________ 15
Results __________ 25
Discussion and post lab
questions ___________ 30
References ___________ 5
Late Penalty __________ –10 pts/calendar day late
Final Report GRADE 100

Experiment 25: Determination of Dissociation Constant of a Weak Acid
Mina Nakhla, Micheal and anthony 03-029-2022
General Chemistry II CHEM 1204
Justin Bogart
Department of Chemistry and Biochemistry Maxwell Becton College of Arts and Sciences
Fairleigh Dickinson University
Abstract
In this experiment, the ionization constant of an unknown weak acid was determined by
titrating it; it has a strong base (NaOH solution). This was accomplished by using the titration
curve based on the data. The concentration of the unknown acid was also determined by using
the base at the equivalence point, its molarity, and the volume of acid used. The results show that
the ionization constant for the unknown acid was ( ) and the concentration was (1 ) 3. 162 0
−4.5

Introduction:
Acids and bases are important in many areas of chemistry and biology. Chemical
behavior allows us to categorize compounds as acids or bases. An Arrhenius acid is defined as a
chemical that creates hydronium ions ( ) in aqueous solution, whereas an Arrhenius base is 𝐻
3
?
+
defined as a substance that produces hydroxide ions ( ). The Brnsted-Lowry hypothesis ?𝐻
−
provides a more relevant definition of acids and bases. A Brnsted-Lowry acid is defined as a
proton donor, whereas a Brnsted-Lowry base is defined as a proton acceptor
(1) 𝐻𝐶? (𝑎?) + 𝐻
2
? (𝑙) → 𝐻
3
?
+
(𝑎?) + 𝐶𝑙
−
In this reaction, the acid HCl donates a proton ( H+) to a water molecule (the base) to
produce the ions + and Cl-. HCl is a strong acid, which means that ionization is essentially 𝐻
3
?
+
complete; nearly 100% of the HCl in solution has been converted to and Cl- ions. By 𝐻
3
?