Henderson Hasselbalch Relationship and Weak Acid Titration

2019 ◽  
Author(s):  
Marc Blétry
Keyword(s):  
Theoretical Framework ◽  
Weak Acid ◽  
Acid Base ◽  
Sensitive Technique ◽  
Chemistry Students ◽  
Advanced Students ◽  
Acid Titration ◽  
Acid Base Titration ◽  
Analytical Expressions

Henderson-Hasselbalch relation is generally the simplified theoretical framework used to introduce students to acid-base titration. However, it is not always valid and its limitations should be made clear to chemistry students. The appropriate parameter to evaluate its validity is K a /C 0 , in connection with Ostwald dilution law. For more advanced students, it is possible to deduce analytical expressions that always fit accurately acid-base titrations and allow an evaluation of Henderson Hasselbalch relation. Gran plot appears as a particularly sensitive technique to the breakdown of Henderson Hasselbalch relation.

Henderson Hasselbalch Relationship and Weak Acid Titration

2019 ◽  
Author(s):  
Marc Blétry
Keyword(s):  
Theoretical Framework ◽  
Weak Acid ◽  
Acid Base ◽  
Sensitive Technique ◽  
Chemistry Students ◽  
Advanced Students ◽  
Acid Titration ◽  
Acid Base Titration ◽  
Analytical Expressions

Henderson-Hasselbalch relation is generally the simplified theoretical framework used to introduce students to acid-base titration. However, it is not always valid and its limitations should be made clear to chemistry students. The appropriate parameter to evaluate its validity is K a /C 0 , in connection with Ostwald dilution law. For more advanced students, it is possible to deduce analytical expressions that always fit accurately acid-base titrations and allow an evaluation of Henderson Hasselbalch relation. Gran plot appears as a particularly sensitive technique to the breakdown of Henderson Hasselbalch relation.

scholarly journals Flower Extracts of Cage Plants (Canavalia virosa) as an Indicator of Acid Base

2020 ◽  
Vol 9 (4) ◽  
pp. 191-198
Author(s):  
Andi M. Rendi ◽  
Supriadi Supriadi ◽  
Suherman Suherman
Keyword(s):  
Strong Acid ◽  
Weak Acid ◽  
Acid Base ◽  
Buffer Solution ◽  
Strong Base ◽  
Flower Extract ◽  
Acid Titration ◽  
Acid Base Titration ◽  
Plant Flower ◽  
Light Green

Cage plants (Canavalia virosa) are classified as nuts. This study aims to prove the flowers of the cage plants as acid-base indicators and determine the type of acid-base titration that is suitable for indicators of cage plants. The flowers of the cage plants were macerated with ethanol. Extras were tested as indicators in acid-base solutions, buffer solutions, and compared with phenolphthalein and methyl orange for acid-base titration, namely: strong acid with a strong base, a weak acid with a strong base, and weak base with strong acid. The results obtained in this study, namely: flower extracts of cage plants in strong red acid, in weak acid pink, in strong green bases, and weak bases in light green. In a buffer solution of pH 1 to pH 11, the flower extract of the cage plants gives 4 color groups, namely: a buffer solution with pH 1 colored red, pH 3 colored pink, pH 5 to pH 9 being light green, and pH 11 being dark blue. Cage plant flower extract can be used as an indicator of acid-base, cage plant flower extract can be used on strong-base strong acid titration, strong weak-acid base, and weak-strong base acid titration.

The Acid–Base Titration of a Very Weak Acid: Boric Acid

2012 ◽  
Vol 89 (6) ◽  
pp. 767-770 ◽  
Author(s):  
M. Celeste C. Azevedo ◽  
Ana M. V. Cavaleiro
Keyword(s):  
Boric Acid ◽  
Weak Acid ◽  
Acid Base ◽  
Acid Base Titration

ETHANOLIC EXTRACT OF ARISTOLOCHIA BRACTEOLATA FLOWER AS A NATURAL INDICATOR FOR ACID-BASE TITRATION

INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (03) ◽  
pp. 77-79
Author(s):  
G Vambhurkar ◽  
A. Jagtap ◽  
A. Gavade ◽  
M Kengar ◽  
M Bhutkar ◽  
...  
Keyword(s):  
Ethanolic Extract ◽  
Strong Acid ◽  
Weak Acid ◽  
Weak Base ◽  
Acid Base ◽  
Ph Indicator ◽  
Strong Base ◽  
Color Changes ◽  
Synthetic Indicators ◽  
Acid Base Titration

In acid-base titration or acid-base neutralization reaction the change in color due to change pH of the solution is caused due to a third substance which is termed as acid-base indicator or pH indicator. Every indicator shows different range of colors at different pH ranges. Synthetic indicators have been widely employed as indicators in acid-base titrations; however, due to environmental pollution, availability and cost, natural compounds are best alternates. Natural pigments in plants are highly colored substances and may show sharp color changes with variation in pH. In the present study an attempt has been made to extract natural indicator from flower of Aristolochia bracteolate. The equivalence points of the titrations namely strong acid-strong base, strong acid-weak base, weak acid-strong base and weak acid weak base titrations, using flower extract of A. bracteolate were coincident with the equivalence points obtained by the synthetic indicator phenolpthalein. From the results of the study, it may be concluded that ethanolic extract of A. bracteolate flower as an indicator for acid-base titration could be effectively employed as a substitute to the synthetic acid-base indicators.

scholarly journals GREEN CHEMISTRY: ROSELLE’S COROLLA EXTRACT AS A SUBSTITUTE FOR HAZARDOUS INTERNAL INDICATORS IN VOLUMETRIC ANALYSIS

2019 ◽  
Vol 7 (9) ◽  
pp. 118-122
Author(s):  
R. F. Pagariya
Keyword(s):  
Strong Acid ◽  
Weak Acid ◽  
Basic Solution ◽  
Phenol Red ◽  
Weak Base ◽  
Acid Base ◽  
Ph Indicator ◽  
Strong Base ◽  
Synthetic Indicators ◽  
Acid Base Titration

Indicators used in acid-base titration show well marked changes of colour in certain intervals of pH. Most of these indicators are organic dyes and are of synthetic origin. Today synthetic indicators are the choice of neutralization titrations. But due to environmental pollution, availability and cost, the search for natural compounds as an acid-base indicator was started. The present work highlights the use of the ethanolic extract of the corolla of Roselle (Hibiscus sabdariffa) as a pH indicator in strong acid-strong base, strong acid weak base, weak acid strong base and weak acid-weak base titrations. This natural indicator is easy to extract as well as easily available. The results showed that the Roselle’s corolla indicator gave red color in acidic solution, while green in basic solution. The comparison indicators used in this research were phenolphthalein, methyl red and phenol red. Hopeful results were obtained when it was compared against standard synthetic indicators. The equivalence points obtained match with the equivalence points obtained by standard indicators. Therefore this natural indicator is found to be useful, economical, simple, precise and eco-friendly for acid base titration.

scholarly journals KAJIAN EKSTRAK ETANOL BUNGA BOGENVIL (Bougenvillea spectabillis Willd) SEBAGAI BIOINDIKATOR ASAM BASA

KOVALEN ◽  
2017 ◽  
Vol 3 (3) ◽  
pp. 277
Author(s):  
Nurhaeni Nurhaeni ◽  
Fitri A Bande ◽  
Rismawaty Sikanna
Keyword(s):  
Color Change ◽  
Ethanol Extract ◽  
Strong Acid ◽  
Weak Acid ◽  
Alkaline Condition ◽  
Acid Base ◽  
Ph Indicator ◽  
Strong Base ◽  
Acid Titration

Studies of ethanol extract of bougainvillea flowers (Bougenvillea spectabillis Willd) as bioindicators of the acid-base has been done. The aims to determine the content of chemical compounds contained in extracts of bougainvillea flowers and bougainvillea flower extract pH stretch. Achievement of the objectives has done through the test of ethanol extract of bougainvillea identification of compounds and the determination of the acid-base stretch of pH indicator is. The obtained results showed that bogenvil ethanol extract containing flavonoids with 401 nm absorption and provided a color change in the acid and alkaline condition the color is yellow. The appropriate acid-base titration is used as bioindicators of a strong acid titration with a strong base, weak acid with a strong base and a weak base with a strong acid.Keywords: Flowers bougainvillea, indicators, bases acid titration

Sign in / Sign up

Export Citation Format

Share Document