Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Bicarbonate-Carbonic Acid Buffer01:22

Bicarbonate-Carbonic Acid Buffer

1.6K
The carbonic acid-bicarbonate buffer system is critical for maintaining the body's pH balance. It operates on the equilibrium:
1.6K
Calculating pH Changes in a Buffer Solution02:45

Calculating pH Changes in a Buffer Solution

53.5K
A buffer can prevent a sudden drop or increase in the pH of a solution after the addition of a strong acid or base up to its buffering capacity; however, such addition of a strong acid or base does result in the slight pH change of the solution. The small pH change can be calculated by determining the resulting change in the concentration of buffer components, i.e., a weak acid and its conjugate base or vice versa. The concentrations obtained using these stoichiometric calculations can be used...
53.5K
Titration of a Weak Acid with a Strong Base01:30

Titration of a Weak Acid with a Strong Base

2.2K
In titrating a weak acid with a strong base, different calculation methods are applied at various stages. Initially, the pH of a weak acid like acetic acid is calculated using its dissociation constant (Ka) and an ICE table. Upon addition of a strong base such as sodium hydroxide, a buffer forms, and its pH is determined using the Henderson-Hasselbalch equation. As more base is added and the titration reaches the halfway point, the pH becomes equal to the pKa of the acid, indicating equal...
2.2K
Common Ion Effect03:24

Common Ion Effect

41.9K
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Châtelier’s principle. Consider the dissolution of silver iodide:
41.9K
Buffer Effectiveness02:19

Buffer Effectiveness

49.2K
Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised.
The buffer capacity is the amount of acid or base that can be added to a given volume...
49.2K
Titration of a Weak Base with a Strong Acid01:20

Titration of a Weak Base with a Strong Acid

5.3K
The titration curve of a weak base like ammonia with a strong acid like hydrochloric acid is the mirror image of the titration curve of a weak acid with a strong base.
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
5.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Isotope Effect on the Hydrogen Ordering from Ice V to Ice XIII via a Partially Ordered Intermediate.

The journal of physical chemistry. B·2026
Same author

Dynamics of coalescence in hyperquenched glassy water probed by x-rays.

The Journal of chemical physics·2026
Same author

Life History Responses of Four Invasive Crayfish Species Under Prolonged Suboptimal Temperatures.

Integrative and comparative biology·2026
Same author

Group-specific effect of interannual water level fluctuation on consumers trophic niche area.

Scientific reports·2026
Same author

Incidence of adverse events in iron-deficient pregnant women and surgical patients undergoing intravenous iron treatment with ferric isomaltose or ferric carboxymaltose: A systematic review.

Transfusion·2026
Same author

Acidity changes in glycine and L-histidine buffers, mannitol, and their mixtures after freezing and lyophilization.

International journal of pharmaceutics·2026

Related Experiment Video

Updated: Jul 24, 2025

Measurement and Analysis of Extracellular Acid Production to Determine Glycolytic Rate
06:47

Measurement and Analysis of Extracellular Acid Production to Determine Glycolytic Rate

Published on: December 12, 2015

25.2K

Investigating freezing-induced acidity changes in citrate buffers.

Behera Susrisweta1, Lukáš Veselý1, Radim Štůsek1

  • 1Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.

International Journal of Pharmaceutics
|July 8, 2023
PubMed
Summary

Citrate buffers used for biomolecule stabilization acidify when frozen. This study identifies optimal buffer concentrations to minimize pH changes during frozen storage.

Keywords:
CryomicroscopyDifferential Scanning CalorimetryFreeze-concentrated solutionGlass Transition TemperatureHammett acidity functionStabilizationSulfonephthalein indicators

More Related Videos

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
08:53

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092

Published on: October 2, 2017

30.2K
Determination of the Gas-phase Acidities of Oligopeptides
11:00

Determination of the Gas-phase Acidities of Oligopeptides

Published on: June 24, 2013

11.2K

Related Experiment Videos

Last Updated: Jul 24, 2025

Measurement and Analysis of Extracellular Acid Production to Determine Glycolytic Rate
06:47

Measurement and Analysis of Extracellular Acid Production to Determine Glycolytic Rate

Published on: December 12, 2015

25.2K
Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
08:53

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092

Published on: October 2, 2017

30.2K
Determination of the Gas-phase Acidities of Oligopeptides
11:00

Determination of the Gas-phase Acidities of Oligopeptides

Published on: June 24, 2013

11.2K

Area of Science:

  • Biochemistry
  • Physical Chemistry
  • Materials Science

Background:

  • Citrate buffers are widely used for stabilizing biomolecules.
  • Understanding buffer behavior in the frozen state is crucial for storage and preservation.

Purpose of the Study:

  • To investigate the pH changes of citrate buffers upon freezing.
  • To determine the influence of initial pH and concentration on freezing-induced acidification.
  • To identify optimal citrate buffer conditions for frozen biomolecule stabilization.

Main Methods:

  • Examined citrate buffer solutions across a pH range of 2.5 to 8.0 and concentrations of 0.02 to 0.60 M.
  • Assessed freezing-induced acidity changes using sulfonephthalein molecular probes.
  • Employed optical cryomicroscopy and differential scanning calorimetry to analyze buffer behavior during freezing and thawing.

Main Results:

  • Citrate buffers exhibit significant acidification upon cooling and freezing.
  • The extent of acidification is dependent on both initial pH and buffer concentration.
  • Buffer solutions undergo partial crystallization and vitrification in the ice matrix, affecting pH.
  • Optimal buffer concentrations were identified for minimal pH change at various pH values.

Conclusions:

  • Citrate buffer pH is altered by freezing due to crystallization and vitrification processes.
  • Knowledge of these pH shifts allows for the design of optimal frozen storage conditions.
  • Selecting appropriate buffer concentrations can mitigate freezing-induced acidification, enhancing biomolecule stability.