Measurement of pH in Acetic Acid-Sodium Acetate Buffer Solutions | Chapter 9 | Chemistry and Biochemistry: Research Progress Vol. 6

A buffer solution refers to a system that has the property of being able to eliminate or diminish the influence of external conditions on a chemical system. In pH determination, various factors influence the pH of a buffer solution, including changes in temperature, ionic strength, hydrogen ion activity, dilution, and the addition of electrolyte salts. Acidic buffers have a pH of less than 7, where for neutral buffer solutions the pH is 7, and if any buffers have a pH of more than 7, it is known as basic buffers, respectively. In this study, the preparation of acetic acid-sodium acetate buffer solutions was reported, and its pH was determined by using a pH meter at about 25°C. In preparation of buffer solutions, firstly, 1.5 ml of glacial acetic acid was taken into a 100 ml standard flask for making up 0.2M of acetic acid solution, and 0.64 g of sodium acetate was dissolved in 100 ml of distilled water. Then, 36.2 ml of prepared solution of sodium acetate was taken into a 100 ml standard flask and 14.8 ml of prepared acetic acid was added to make its volume 100 ml by using distilled water, making it a buffer. In measuring the pH of prepared buffer solutions, a calibrated digital pen pH meter was used for quick resolution of readings with accuracy. The pH of acetic acid-acetate buffer solutions was gradually raised by adding a small quantity of 5N NaOH solution into the buffer sample, and the adjusted pH was adjusted to 4.7. By meticulously outlining the preparation process and employing a calibrated pH meter for precise pH determination, this study enhances the understanding of buffer systems' behaviour when subjected to pH changes. Such insights are crucial for maintaining stable conditions in biochemical experiments and industrial processes, where pH control is vital for optimal performance and reaction outcomes.

 

Author(s) Details

Shiv P. Mishra
Department of Chemistry, Shia PG College, Lucknow-226020, UP, India.

R. P. Singh
K.N.I.P.S.S., Sultanpur-228118, (U.P.), India.

 

Please see the book here:- https://doi.org/10.9734/bpi/cbrp/v6/5689

vStudy and Estimation of Hardness of Water by pH-Metric Titration Method | Chapter 8 | Chemistry and Biochemistry: Research Progress Vol. 5

The hardness of water is one of the most important parameters of water quality. The hardness of water arises primarily due to the presence of a profuse amount of Ca²⁺ and Mg₂₊ ions in the natural water resources. The complexometric titration method is a prevalent technique in estimating the concentrations of Ca²⁺ and Mg²⁺ and  ions individually, which are primarily responsible for the hardness of water. However, the method needs two external indicators to mark the endpoints of titrations. Furthermore, accuracy of the method is sacrificed due to inevitable parallax errors during marking of the endpoint of titration. This present work proposes a novel technique to estimate the concentrations of Ca2+ and Mg2+ ions of a given water sample. Two different hard water samples are prepared to estimate the hardness of water by pH-Metric Titration Method.

 

This present work reports that during titration of a hard water sample with a complexing agent (here, Na2 EDTA solution), pH changes continuously. This change in pH is closely monitored and recorded graphically. The recorded data reveals two distinct linear regions with significantly different slopes, indicating the titration endpoint. The neutralization volume, thus obtained, is used to estimate Ca- and Mg- hardness of the water sample separately. This novel technique obviates the use of any external indicators and eliminates any possible parallax error. Besides conventional spectroscopic and volumetric titration methods, this novel method is believed to be useful to monitor other chemical reactions accurately, exploring future research works. This pH- metric study is expected to have potential in the development of analytical chemistry and chemical processes related to industry.

 

Author (s) Details

 

Abhijit Mallick
Department of Engineering Science (Chemistry), Academy of Technology, P.O. Aedconagar, Adisaptagram, District- Hooghly, 712121, West Bengal, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/cbrp/v5/5054