There are various ions that are responsible for the acidic or basic nature of a substance. The hydrogen ions and hydroxide ions are both responsible for the acidic and basic nature of substance respectively. A neutral substance contains equal number of hydrogen ions (H+) as well as hydroxide ions (OH-) An acid is substance that dissolve and donate hydrogen ions leading to more number of hydrogen ions in a solution. A substance that dissolves water and release hydroxide ions is considered a base. A base has more number of hydroxide ions as compared to hydrogen ions hence basic.
Alkalinity (basic) and acidic nature of a substance is measured by the use of logarithmic scale that is known as pH scale. The pH is very important for the measurement as it gives more details for instance the level of acidity as well level of alkalinity in solution. pH is the negative logarithm of the hydrogen ion concentration as shown below (Huck and Leigh 1339-1348).
pH= -log[H+]
The pH scale ranges from 1 to 14 with different values assigned to different concentrations of the substance. 1- 6.9 shows the level of acidity with 1 representing the most acidic and 6.9 representing the least basic substance.7 represents neutral while 7.1 to 14 represents the most alkalinity range. Apart from ph scale litmus papers (Red and Blue) can be used as indicator of alkalinity and acidity.
Acid and base reacts to form salt and water. This reaction is known as neutralization reaction. It involves the combination of both the hydrogen ions H+ and hydroxide ions OH- to form water molecules. The result from the reaction has PH scale of 7.
Acid+Base→Salt+Water.
Sodium hydroxide is an example of alkaline substance while hydrochloric acid is an example of acidic substance. The two reacts to form sodium chloride and water.
The reaction is as shown below
NaOH+HCl→NaCl+H2O.
Acid and base titration involve finding the amount of base or acid through acid base reaction. The titrant (analyte) has unknown molarity while reagent has known molarity. In titration indicator is used to determine the end point of the neutralization. The process involves measuring specific amount of reagent having known concentration (Huck and Leigh 1339-1348). The measured reagent is poured into the volumetric flask. Drops of indicator is added into the reagents. The titrant (a solution with unknown concentration) is poured in burette until it reaches the specified mark. The titrant is the burette is then released into the volumetric flask containing the reagent. The color is then keenly observed during the titration process. Color change marks the end point if titration (Tajima, Kishi and Nakajima 5959-5963). The titrant volume (burette) volume used for the reaction is measured. For known volume, molarity can be calculated.
Below are samples of acids and their uses.
Works cited
Tajima, Toshiki, Yuichiro Kishi, and Atsushi Nakajima. "Anodic Acyloxylation Based On The Acid–Base Reactions Between Acetic Acid Or Trifluoroacetic Acid And Solid-Supported Bases". Electrochimica Acta 54.24 (2009): 5959-5963. Web.
Huck, Lawrence A. and William J. Leigh. "Substituent Effects On The Reactions Of Diarylgermylenes And Tetraaryldigermenes With Acetic Acid And Other Lewis Bases In Hydrocarbon Solution". Organometallics 26.6 (2007): 1339-1348. Web.
