Acid

Definition

An acid is a substance that donates hydrogen ions (H+) when dissolved in water, resulting in a pH lower than 7. Acids are crucial in many biological and chemical processes, influencing the structure and function of molecules in living organisms.

5 Must Know Facts For Your Next Test

1. Acids increase the concentration of hydrogen ions (H+) in a solution.
2. The pH scale measures acidity, with values below 7 indicating acidic solutions.
3. Common examples of acids include hydrochloric acid (HCl) and acetic acid (CH3COOH).
4. Acids can denature proteins and affect enzyme activity due to changes in pH.
5. In biological systems, acids play essential roles such as aiding digestion in the stomach.

Review Questions

• What effect does an acid have on the concentration of hydrogen ions in a solution?
• How does the pH scale indicate an acidic solution?
• Why are acids important for biological processes?

Related terms

Base: A substance that accepts hydrogen ions (H+) and has a pH greater than 7.

pH Scale: A logarithmic scale used to measure the acidity or basicity of a solution.

Buffer: A solution that resists changes in pH by neutralizing added acids or bases.