Acids and Bases: Understanding Acidic and Basic Substances
Acids and bases are water-soluble compounds that can cause irritation and corrosion. Understanding the difference between these two substances is crucial, as it impacts the chemical reactions they produce in contact with other substances.
Acidic substances dissolve in water and release hydrogen ions (H+), which transform into hydronium ions (H3O+). Substances like vinegar and lemon juice showcase their sour taste and are examples of acidic substances.
Ways to Obtain Acidic Substances
You can obtain acidic substances by:
- Reacting anhydrides with water to form oxyacids. For instance, the reaction of sulfur trioxide (SO3) and water (H2O) produces sulfuric acid (H2SO4).
SO3 + H2O = H2SO4
Sulfur trioxide + water ⏩ Sulfuric acid
- Combining hydrogen (H) with a non-metal to form hydracids. For example, the reaction of hydrogen (H2) and chlorine (Cl2) produces hydrochloric acid (2HCl).
H2 + CL2 = 2HCL
hydrogen + chlorine ⏩ Hydrochloric acid
Basic substances, also known as alkalis, dissolve in water and increase the concentration of hydroxyl ions (OH-). Examples of basic substances include bicarbonate and soap, which are characterized by their bitter taste.
Ways to Obtain Basic Substances
You can obtain basic substances by reacting metal oxides with water to form hydroxides. The molecule of hydroxides contains at least one hydroxyl group (OH-), which is formed by an oxygen atom bonded with a hydrogen atom and has a negative electric charge. For example, the reaction of sodium oxide (Na2O) and water (H2O) produces sodium hydroxide (NaOH), also known as caustic soda.
Na2O + H2O = 2NaOH
sodium oxide + water ⏩ Sodium hydroxide
Sodium hydroxide is an aggressive substance (called caustic soda) used to clear clogged sink drains.
Measuring the Acidity of a Solution
To measure the acidity or basicity of a solution, scientists use the pH scale. This scale measures the concentration of hydrogen ions (H+) in a solution. In liquid water, a small number of molecules tend to dissociate spontaneously into ions (H+) and hydroxyl ions (OH-).
Acids and bases are important substances in chemistry and have various applications. By understanding the difference between acidic and basic substances and the ways to obtain them, we can appreciate the impact they have on our daily lives.