Understanding The Chemical Properties Of Acids, Bases, And Salts

key notes :-

Acids

• Definition: Acids are substances that release hydrogen ions (H⁺) when dissolved in water. They have a pH less than 7.
• Taste: Acids generally have a sour taste (e.g., lemon juice, vinegar).

• Reaction with Metals: Acids react with certain metals (e.g., Zn, Mg) to produce hydrogen gas and a salt.
  • Example: Zn +2HCl → ZnCl₂ +H₂
• Reaction with Bases (Neutralization): Acids react with bases to form water and a salt.
  • Example: HCl + NaOH → NaCl + H₂O
• Indicators: Acids turn blue litmus paper red.

Bases

• Definition: Bases are substances that release hydroxide ions (OH⁻) when dissolved in water. They have a pH greater than 7.
• Taste and Feel: Bases typically have a bitter taste and feel slippery (e.g., soap, baking soda).

• Reaction with Acids (Neutralization): Bases neutralize acids to produce water and a salt.
  • Example: NaOH + HCl → NaCl + H₂O
• Reaction with Ammonium Salts: Bases react with ammonium salts to release ammonia gas.
  • Example: NH₄Cl + NaOH → NH₃ +H₂O + NaCl
• Indicators: Bases turn red litmus paper blue.

Salts

• Definition: Salts are ionic compounds formed from the neutralization reaction between an acid and a base.

• Formation: Salt formation can occur through various reactions:
  • Acid + Base: Produces salt and water (neutralization).
  • Acid + Metal: Produces salt and hydrogen gas.
  • Acid + Metal Carbonate: Produces salt, water, and carbon dioxide.
• Examples of Salts: Sodium chloride (NaCl), calcium carbonate (CaCO₃), potassium nitrate (KNO₃).
• pH of Salts: The pH of a salt solution can be acidic, basic, or neutral, depending on the strengths of the parent acid and base.

pH Scale

• Definition: The pH scale measures the acidity or basicity of a solution. It ranges from 0 to 14.

• pH < 7: Acidic
• pH = 7: Neutral
• pH > 7: Basic
• Importance: pH is crucial in various chemical processes, biological systems, and industrial applications.

Indicators

• Definition: Indicators are substances that change color in the presence of an acid or base.
• Common Indicators:
• Litmus: Red in acid, blue in base.

• Phenolphthalein: Colorless in acid, pink in base.

• Methyl Orange: Red in acid, yellow in base.

Applications of Acids, Bases, and Salts

• Acids: Used in food preservation, cleaning agents, and manufacturing (e.g., sulfuric acid in batteries).
• Bases: Used in soap production, baking, and antacid tablets.
• Salts: Used in cooking, fertilizers, and as preservatives.

Safety Precautions

• Handling Acids and Bases: Always wear protective gear (gloves, goggles) when handling strong acids or bases. Avoid direct contact with skin and eyes.
• Storage: Acids and bases should be stored in properly labeled containers and kept away from each other to prevent accidental reactions.

Let’s practice!