Chemistry Acids and Bases

Acids

• Definition: A substance that donates a proton (H+ ion) in a solution
• Characteristics:
  • Taste sour
  • Turn litmus paper red
  • React with metals to produce hydrogen gas
  • Increase the concentration of H+ ions in a solution
• Examples:
  • Hydrochloric acid (HCl)
  • Sulfuric acid (H2SO4)
  • Nitric acid (HNO3)
  • Acetic acid (CH3COOH)

Bases

• Definition: A substance that accepts a proton (H+ ion) in a solution
• Characteristics:
  • Taste bitter
  • Turn litmus paper blue
  • Feel slippery to the touch
  • Decrease the concentration of H+ ions in a solution
• Examples:
  • Sodium hydroxide (NaOH)
  • Calcium hydroxide (Ca(OH)2)
  • Ammonia (NH3)
  • Baking soda (NaHCO3)

Salts

• Definition: A compound formed by the reaction of an acid and a base
• Characteristics:
  • Neutral in nature (pH 7)
  • Do not affect the pH of a solution
  • Can be formed through various methods, including:
    • Reaction of an acid and a base
    • Reaction of an acid and a metal oxide
    • Reaction of a base and a metal carbonate
• Examples:
  • Sodium chloride (NaCl)
  • Calcium carbonate (CaCO3)
  • Aluminum sulfate (Al2(SO4)3)
  • Copper nitrate (Cu(NO3)2)

pH Scale

• A scale used to measure the acidity or basicity of a solution
• Ranges from 0-14, with:
  • 0-1: Strongly acidic
  • 2-3: Acidic
  • 4-5: Weakly acidic
  • 6-7: Neutral
  • 8-9: Weakly basic
  • 10-14: Basic
• pH is calculated using the formula: pH = -log[H+]

Acids

• Donates a proton (H+ ion) in a solution
• Sour taste
• Turns litmus paper red
• Reacts with metals to produce hydrogen gas
• Increases concentration of H+ ions in a solution
• Examples: HCl, H2SO4, HNO3, CH3COOH

Bases

• Accepts a proton (H+ ion) in a solution
• Bitter taste
• Turns litmus paper blue
• Feels slippery to the touch
• Decreases concentration of H+ ions in a solution
• Examples: NaOH, Ca(OH)2, NH3, NaHCO3

Salts

• Formed by reaction of acid and base
• Neutral in nature (pH 7)
• Does not affect pH of a solution
• Can be formed through:
  • Acid-base reaction
  • Acid-metal oxide reaction
  • Base-metal carbonate reaction
• Examples: NaCl, CaCO3, Al2(SO4)3, Cu(NO3)2

pH Scale

• Measures acidity/basicity of a solution
• Ranges from 0-14
• pH levels:
  • 0-1: Strongly acidic
  • 2-3: Acidic
  • 4-5: Weakly acidic
  • 6-7: Neutral
  • 8-9: Weakly basic
  • 10-14: Basic
• pH formula: pH = -log[H+]