Acids, Bases, and Salts Lecture

Introduction to Acids and Bases

• Acids

  • Sour in taste
  • Found in daily items:
    • Curd (Lactic acid)
    • Lemon (Citric acid)
    • Vinegar (Acetic acid)

• Bases

  • Bitter in taste
  • Soapy to touch
  • Found in:
    • Detergents
    • Toothpaste
    • Hair dyes

Testing Acids and Bases

• Indicators

  • Litmus
    • Blue litmus turns red in acid
    • Red litmus turns blue in base
  • Natural Indicators
    • Red cabbage, turmeric, hibiscus
  • Synthetic Indicators
    • Methyl orange: Red in acid, yellow in base
    • Phenolphthalein: Colorless in acid, pink in base

• Olfactory Indicators

  • Onion, vanilla essence, clove oil can indicate acids/bases by smell

Reactions of Acids and Bases

• With Metals

  • Acid + Metal → Salt + Hydrogen gas
  • Base + Metal → Salt + Hydrogen gas

• With Metal Carbonates/Hydrogen Carbonates

  • Carbonates/Hydrogen Carbonates + Acid → Salt + Water + CO2

• Neutralization Reactions

  • Acid + Base → Salt + Water

• With Metal Oxides

  • Metal oxides + Acid → Salt + Water

• With Non-Metal Oxides

  • Base + Non-metal oxide → Salt + Water

Conductivity and Dilution

• Acids and bases conduct electricity due to ion formation in water
• Dilution involves mixing with water, reducing ion concentration
• Always add acid to water to prevent splashing

Strength of Acids and Bases

• Measured using pH Scale (0-14)
  • Neutral: pH 7
  • Acidic: pH < 7
  • Basic: pH > 7

Importance of pH

• Aquatic Life: pH affects health of water bodies
• Plant Growth: Soil pH is crucial for plants
• Human Body:
  • Stomach acid (HCl) aids digestion
  • Tooth decay caused by pH drop from bacterial acids

Acids and Bases in Self-Defense

• Animal Defense: Bee stings (acidic), use baking soda
• Plant Defense: Natural leaf stings neutralized by rubbing with dog plant

Salts

• Nature of Salts
  • Neutral, acidic, or basic
  • Derived from various acid-base combinations

Sodium Chloride and Related Compounds

• Common Salt Uses

  • Base for making caustic soda, baking soda, washing soda, bleaching powder

• Chlor Alkali Process

  • Produces sodium hydroxide, chlorine gas, and hydrogen gas

• Uses of Products

  • Chlorine: Water treatment, PVC, disinfectants
  • Hydrogen: Fuel, margarine, fertilizers
  • Sodium hydroxide: Soaps, detergents

Baking Soda

• Used in cooking, as an antacid, in fire extinguishers

Washing Soda

• Used in manufacturing, cleaning, removing water hardness

Bleaching Powder

• Used in whitening, as an oxidizing agent, disinfecting

Plaster of Paris

• Made by heating gypsum
• Used in medicine for bone supports, making models

Please subscribe to the channel for more educational content.