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Demystifying Acids, Bases, & Salts: Your Guide to Mastering Class 10 NCERT Chemistry

ACIDS, BASES, AND SALTS: An Insightful Exploration for Class 10 NCERT Students

Chemical Properties of Acids and Bases

Acids and bases are two fundamental classes of substances with distinct chemical properties.

Acids are substances that produce hydrogen ions (H⁺) when dissolved in water. They typically have a sour taste and can corrode metals. Examples include hydrochloric acid (HCl) and sulfuric acid (H₂SO₄).

Bases, on the other hand, are substances that produce hydroxide ions (OH⁻) in solution. They usually have a bitter taste and a slippery feel. Common examples are sodium hydroxide (NaOH) and ammonia (NH₃).

Key Reactions:
  1. Reaction with Metals: Acids react with most metals to form a salt and hydrogen gas. [ Acid + Metal → Salt + Hydrogen Gas ]
  2. Reaction with Metal Carbonates and Bicarbonates: Both acids and bases react with carbonates to produce carbon dioxide, water, and a salt. [ Acid/Base + Carbonate → Salt + Water + Carbon Dioxide ]
  3. Neutralization Reaction: Acids and bases react with each other to form a salt and water in a neutralization reaction. [ Acid + Base → Salt + Water ]

Similarities in Acids and Bases

Despite their differences, acids and bases share some common characteristics:

  1. Conduct Electricity: Both acids and bases conduct electricity when dissolved in water due to the presence of ions.
  2. Corrosive Nature: Strong acids and bases are corrosive and can damage skin and materials.
  3. Indicator Change: They change the color of indicators; acids turn blue litmus red, while bases turn red litmus blue.

Strength of an Acid or Base Solution

The strength of an acid or a base in a solution is determined by its ability to dissociate into ions.

  • Strong Acids and Bases completely dissociate into their ions in solution, like HCl and NaOH.
  • Weak Acids and Bases partially dissociate, like acetic acid (CH₃COOH) and ammonia.

Information About Salts

Salts are compounds formed by the neutralization reaction between an acid and a base. They have a wide range of uses in our daily lives, including in cooking, cleaning, and in various industrial processes.

Types of Salts:
  1. Normal Salts: Formed by the complete replacement of hydrogen in acids by metals or ammonium ion.
  2. Acid Salts: Formed by the partial replacement of hydrogen ions in a dibasic or tribasic acid.
  3. Basic Salts: Formed by the incomplete neutralization of a base.
Properties of Salts:
  • Solubility: Most salts are soluble in water but insoluble in non-polar solvents.
  • Electrical Conductivity: They conduct electricity in molten or solution state due to the presence of ions.
  • pH: The pH of salt solutions varies; salts of strong acids and bases are neutral, while those of a strong acid and weak base are acidic, and vice versa.


Understanding acids, bases, and salts is crucial in the field of chemistry. Their varied properties and reactions form the foundation of numerous chemical processes, both in nature and in industrial applications.

Acids and Bases: A Balancing Act in Chemistry

Ever wondered why lemons taste sour and vinegar cleans windows? It’s all thanks to their magical properties as acids and bases. These amazing chemicals play a crucial role in everyday life, from cooking and cleaning to medicine and manufacturing. Let’s explore the fascinating world of acids and bases and see how they dance together.

Chemical Properties of Acids and Bases:

  • Acids: These are sour-tasting substances that release hydrogen ions (H+) in water. They typically turn blue litmus paper red and react with metals to produce hydrogen gas. Examples include hydrochloric acid (HCl), sulfuric acid (H2SO4), and acetic acid (CH3COOH).
  • Bases: These are slippery substances that release hydroxide ions (OH-) in water. They turn red litmus paper blue and feel soapy to touch. Examples include sodium hydroxide (NaOH), potassium hydroxide (KOH), and ammonia (NH3).

Similarities in Acids and Bases:

  • Electrical Conductors: Both acids and bases can conduct electricity when dissolved in water, making them essential in battery production and electroplating.
  • Neutralization: When an acid and a base react in specific amounts, they neutralize each other, forming water and a salt. This reaction plays a vital role in many biological processes, like regulating pH in our bodies.
  • Corrosive Nature: Strong acids and bases can be corrosive, meaning they can damage and dissolve materials like metals and tissues. Handling them with proper safety precautions is important.

Strength of an Acid or Base Solution:

  • pH Scale: The strength of an acid or base is measured on the pH scale, ranging from 0 to 14. Acids have a pH less than 7, bases have a pH greater than 7, and neutral solutions have a pH of 7.
  • Concentration: The concentration of an acid or base in a solution also affects its strength. A more concentrated solution has a higher number of ions and is therefore stronger.

Information about Salts:

  • Salt Formation: When an acid and a base react, they produce water and a salt. Salts are typically ionic compounds and can be neutral, acidic, or basic depending on the nature of the parent acid and base.
  • Properties of Salts: Some salts like table salt (NaCl) are soluble in water and conduct electricity. Others like calcium carbonate (CaCO3) are insoluble and used in construction materials.

Acids and bases are not just confined to the lab; they are all around us in our daily lives. Understanding their properties helps us appreciate their applications and use them safely and effectively. Whether it’s brewing a cup of coffee with lemon or cleaning your bathroom with vinegar, remember that acids and bases are constantly performing behind the scenes, making our lives a little brighter and cleaner.

Remember, safety first! Always wear gloves and goggles when handling strong acids and bases and follow proper safety procedures.

Here are 10 important questions and answers on the topic of acids, bases, and salts, tailored for students studying at the class 10 level:

  1. Q: What is an acid? Give two examples.
  • A: An acid is a substance that produces hydrogen ions (H⁺) when dissolved in water. Examples include hydrochloric acid (HCl) and sulfuric acid (H₂SO₄).
  1. Q: What are the properties of bases?
  • A: Bases taste bitter, feel slippery, and turn red litmus paper blue. They produce hydroxide ions (OH⁻) in water. Examples include sodium hydroxide (NaOH) and ammonia (NH₃).
  1. Q: Define neutralization reaction with an example.
  • A: Neutralization is a chemical reaction in which an acid and a base react to form salt and water. For example, hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH) to form sodium chloride (NaCl) and water (H₂O).
  1. Q: How do acids react with metals?
  • A: Acids react with most metals to form a salt and hydrogen gas. For example, zinc reacts with hydrochloric acid to form zinc chloride and hydrogen gas.
  1. Q: What is the pH scale and what does it measure?
  • A: The pH scale measures how acidic or basic a substance is, on a scale from 0 to 14. A pH less than 7 indicates an acidic solution, pH 7 is neutral, and pH greater than 7 indicates a basic solution.
  1. Q: Give two examples of salts and their uses.
  • A: Sodium chloride (NaCl), used as table salt for flavoring food, and calcium carbonate (CaCO₃), used in antacids to relieve heartburn and indigestion.
  1. Q: What is the difference between a strong acid and a weak acid?
  • A: A strong acid completely dissociates into ions in water, like hydrochloric acid (HCl). A weak acid partially dissociates, like acetic acid (CH₃COOH).
  1. Q: What are acid salts? Give an example.
  • A: Acid salts are formed by the partial replacement of hydrogen ions in a dibasic or tribasic acid. An example is sodium hydrogen carbonate (NaHCO₃).
  1. Q: Why do acids turn blue litmus paper red?
  • A: Acids turn blue litmus paper red due to their acidic nature, which is characterized by the presence of excess hydrogen ions (H⁺) in solution.
  1. Q: Describe how baking soda can be used to neutralize stomach acid.
    • A: Baking soda (sodium bicarbonate, NaHCO₃) is a base that reacts with the hydrochloric acid in the stomach to form sodium chloride, water, and carbon dioxide, thereby neutralizing the stomach acid and relieving indigestion.