Detailed Summary
This section dives into the core concepts of acids, bases, and salts.
Definitions:
- Acids: Substances that release H⁺ ions in aqueous solutions.
- Bases: Substances that release OH⁻ ions in aqueous solutions.
- Salts: Compounds formed when acids react with bases in a neutralization reaction.
Properties:
- Acids typically taste sour, turn blue litmus paper red, react with metals to release hydrogen gas, and conduct electricity due to their ion content. Common examples include Hydrochloric acid (HCl) and Sulphuric acid (H₂SO₄).
- Bases are known for their bitter taste, slippery feel, turning red litmus paper blue, and conducting electricity when dissolved in water. Examples include Sodium hydroxide (NaOH) and Calcium hydroxide (Ca(OH)₂).
pH Scale:
The pH scale measures the acidity or alkalinity of a solution, ranging from 0 to 14, with values below 7 indicating acidity, 7 being neutral (pure water), and above 7 indicating basicity.
Neutralization Reaction:
Describing reactions between acids and bases, resulting in salts and water, the general formula is:
Acid + Base → Salt + Water. For example, in the reaction of HCl with NaOH, the products are NaCl and water.
Types of Salts:
- Normal Salts: Fully replace hydrogen from the acid. Example: NaCl.
- Acid Salts: Partially replace hydrogen. Example: NaHSO₄.
- Double Salts: Formed by combining two different salts. Example: Potash alum (KAl(SO₄)₂·12H₂O).
Preparation of Salts:
Salts can be created through various methods including neutralization, reactions with metals, carbonates, metal oxides, and other salts.
Common Uses:
Acids and bases play vital roles in various industries, including fertilizers and cleaning agents. Their significance in biological processes also cannot be understated.
Indicators:
Substances like litmus paper and phenolphthalein that change color in acidic or basic environments help determine the pH level of solutions.