When acid is added to distilled water, the pH of the distilled water decreases. This is because the acid introduces hydrogen ions (H+), which increase the concentration of hydrogen ions in the solution, leading to a lower pH.
The Science Behind the pH of Distilled Water
Distilled water, which is pure H2O without contamination, initially has a neutral pH of 7. However, as soon as it comes into contact with air or carbon dioxide, it becomes slightly acidic with a pH of around 5.8.
Impact of Adding Acid to Distilled Water
When an acid is added to distilled water, the concentration of hydrogen ions (H+) increases. This leads to a decrease in the pH of the solution. The extent of the pH decrease depends on the concentration and type of acid added. For example, if a strong acid like hydrochloric acid (HCl) is added, the pH will decrease significantly, whereas a weak acid will have a less pronounced effect.
How the pH of Distilled Water Changes
The pH of distilled water changes when acid is introduced to it because of the increase in hydrogen ions. The more acid added, the lower the pH will be. This is because the acid dissociates into hydrogen ions and anions, increasing the concentration of hydrogen ions in the solution. The pH scale is logarithmic, so a small change in the concentration of hydrogen ions can result in a significant change in pH.
Helpful pH Quantity to Consume
For human consumption, a pH range of 6.9 to 7.5 is considered suitable. This is because the human body has a natural pH of around 7.4, and water with a pH close to this range is less likely to cause any adverse effects.
Balancing pH
To balance the pH of distilled water after adding acid, you can add a base such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). The amount of base needed will depend on the concentration and type of acid added. It is essential to carefully monitor the pH during this process to avoid over-correction, which can lead to an alkaline solution.
History
The concept of pH was first introduced by Danish chemist Søren Sørensen in 1909. He defined pH as the negative logarithm of the concentration of hydrogen ions in a solution. Since then, pH has become a crucial parameter in various fields, including chemistry, biology, medicine, and environmental science.
Contaminants and Chemicals
Distilled water can be contaminated by various substances, including:
- Carbon dioxide: When distilled water comes into contact with air, carbon dioxide dissolves in it, forming carbonic acid, which lowers the pH.
- Impurities: Distilled water can contain impurities like minerals, salts, or other substances that can affect its pH.
- Acids and bases: Adding acids or bases to distilled water can significantly alter its pH.
Solutions and Alternatives
To maintain the pH of distilled water, it is essential to store it in tightly sealed containers and minimize its exposure to air. If the pH needs to be adjusted, adding a base or acid in controlled amounts can help achieve the desired pH. For specific applications, alternative types of water, such as deionized or demineralized water, may be more suitable.
References
- Westlab Canada. (2023, July 12). The Science Behind the pH of Distilled Water. Retrieved from https://www.westlab.com/blog/the-science-behind-the-ph-of-distilled-water
- Byju’s. (n.d.). What will happen to PH valve when we add some water to acid or base? Retrieved from https://byjus.com/question-answer/what-will-happen-to-ph-valve-when-we-add-some-water-to-acid-or-base/
- Seattle PI. (n.d.). What Happens to the PH of an Acidic Solution As Pure Water Is Added. Retrieved from https://education.seattlepi.com/happens-ph-acidic-solution-pure-water-added-6028.html
- ChemistNate. (2022, January 22). Effect of adding Water on the pH of the Strong Acid. Retrieved from https://www.youtube.com/watch?v=Rju8yfHQ61M
- The Chemistry Blog. (n.d.). What Is The pH of Distilled Water? Retrieved from https://www.chemicals.co.uk/blog/ph-of-distilled-water.