Chemistry Class: Acids, Bases, and Salts

Acids

• Definition: Substances that donate protons (H⁺ ions) in aqueous solution.
• Characteristics:
  • Sour taste
  • Conduct electricity when dissolved in water
  • Change blue litmus paper to red
• Common Examples:
  • Hydrochloric acid (HCl)
  • Sulfuric acid (H₂SO₄)
  • Acetic acid (CH₃COOH)
• Strong vs. Weak Acids:
  • Strong acids completely dissociate in water (e.g., HCl).
  • Weak acids partially dissociate (e.g., acetic acid).

Bases

• Definition: Substances that accept protons or donate hydroxide ions (OH⁻) in solution.
• Characteristics:
  • Bitter taste
  • Slippery feel
  • Change red litmus paper to blue
• Common Examples:
  • Sodium hydroxide (NaOH)
  • Potassium hydroxide (KOH)
  • Calcium carbonate (CaCO₃)
• Strong vs. Weak Bases:
  • Strong bases fully dissociate in water (e.g., NaOH).
  • Weak bases partially dissociate (e.g., ammonium hydroxide).

Salts

• Definition: Ionic compounds formed from the neutralization reaction of an acid and a base.
• Formation:
  • Acid + Base → Salt + Water
• Characteristics:
  • Typically crystalline solids
  • Can be soluble or insoluble in water
  • Do not affect litmus paper color
• Common Examples:
  • Sodium chloride (NaCl) - formed from HCl and NaOH
  • Potassium sulfate (K₂SO₄) - formed from sulfuric acid and potassium hydroxide
• Uses:
  • Culinary (e.g., table salt)
  • Industrial (e.g., fertilizers, pharmaceuticals)

pH Scale

• Definition: A scale used to measure the acidity or basicity of a solution.
• Scale Range: 0 to 14
  • pH < 7: Acidic
  • pH = 7: Neutral
  • pH > 7: Basic
• Importance: Determines the strength of acids and bases in solutions, influencing chemical reactivity and biological processes.

Acids

• Acids donate protons (H⁺ ions) in aqueous solutions, defining their chemical behavior.
• Characterized by a sour taste, they can conduct electricity when dissolved in water.
• Acids turn blue litmus paper red, indicating their acidic nature.
• Common examples of acids include hydrochloric acid (HCl), sulfuric acid (H₂SO₄), and acetic acid (CH₃COOH).
• Strong acids like HCl fully dissociate in water, while weak acids such as acetic acid only partially dissociate.

Bases

• Bases accept protons or donate hydroxide ions (OH⁻) in solutions, impacting their reactivity.
• They have a bitter taste and a slippery feel, distinguishing them from acids.
• Bases convert red litmus paper to blue, signifying their basic nature.
• Common bases include sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium carbonate (CaCO₃).
• Strong bases like NaOH completely dissociate in water, whereas weak bases, such as ammonium hydroxide, only partially dissociate.

Salts

• Salts are ionic compounds formed through the neutralization of an acid and a base.
• The general reaction is: Acid + Base → Salt + Water.
• Salts are typically crystalline solids, which can be either soluble or insoluble in water.
• They do not influence the color of litmus paper, remaining neutral in this respect.
• Examples include sodium chloride (NaCl) from the reaction of HCl and NaOH, and potassium sulfate (K₂SO₄) from sulfuric acid and potassium hydroxide.
• Salts have various uses, including culinary applications (e.g., table salt) and industrial uses (e.g., fertilizers and pharmaceuticals).

pH Scale

• The pH scale measures the acidity or basicity of a solution, with a range from 0 to 14.
• A pH less than 7 indicates an acidic solution, a pH of 7 represents a neutral solution, and a pH greater than 7 signifies a basic solution.
• The pH of a solution is crucial for determining the strength of acids and bases, affecting chemical reactions and biological processes significantly.

This quiz covers the definitions, characteristics, and examples of acids, bases, and salts. Test your understanding of strong and weak acids and bases, as well as their behavior in aqueous solutions. Perfect for chemistry students looking to solidify their knowledge in this fundamental area.