Untitled Quiz

General Chemistry for Pharmaceutical Sciences (PHARM-101)

• Course presented by Dr. Azza H. Rageh, Associate Professor of Pharmaceutical Analytical Chemistry at Taibah University
• Course covers Stoichiometry, Solution Concentration, and Chemical Reactions
• Specifically, the course covers Reaction Stoichiometry, Solution Concentration, and Types of Aqueous Solutions

Stoichiometry

• Stoichiometry is the calculation of reactant and product quantities in a chemical reaction
• It allows predicting product amounts based on reactant amounts
• Also, it calculates the necessary reactants for a desired product amount

Reaction Stoichiometry

• Balanced chemical equations show relative amounts (in moles)
• Example: 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O
• 2 moles of C8H18 react with 25 moles of O2 to form 16 moles of CO2 and 18 moles of H2O

Concentration of Solutions

• Concentration is the amount of solute in a solution
• Units include: percent weight (% w/w), percent volume (% v/v), percent weight per volume (% w/v), parts per million (ppm), parts per billion (ppb), molarity (M), formality (F), normality (N), and molality (m)
• Molarity (M) = moles of solute/ liter of solution

Types of Aqueous Solutions

• Salt water: homogeneous mixture of NaCl and H₂O
• Sugar water: homogeneous mixture of C₁₂H₂₂O₁₁ and H₂O
• Solutes dissolve in solvents due to attractive forces

Dissolving Process

• Solute particles are attracted to each other
• Attractive forces between solvent molecules exist
• When mixing, forces between solute and solvent arise
• Solute dissolves if these forces are strong enough

Electrolytes and Nonelectrolytes

• Electrolytes dissolve in water, forming solutions that conduct electricity
• Strong electrolytes fully ionize in water (e.g., ionic salts, strong acids, strong bases)
• Weak electrolytes partially ionize (e.g., weak acids, weak bases)
• Nonelectrolytes don't ionize (e.g., sugar, alcohol)

Types of Chemical Reactions

• Synthesis: two or more reactants combine to form a single product (A + B → AB)
• Decomposition: a single compound breaks down into its simpler parts (AB → A + B)
• Replacement (Single): a single element replaces another element in a compound (A + BC → AC + B)
• Replacement (Double): anions and cations of two compounds swap places (AB + CD → AD + CB)

Chemical Reactions between Ions

• Ions combine to form:
  • Water
  • Weak electrolytes
  • Precipitates (insoluble salts)
  • Gases
  • Complex ions

Acid-Base Reactions (Formation of Water)

• Mixing a metallic hydroxide (e.g., NaOH, NH₄OH) with an acid (e.g., HCl) produces water and a salt

Formation of Weak Electrolytes (e.g., Weak Acids)

• Mixing a strong acid (e.g., HCl) with a salt containing the anion of a weak acid (e.g. CH₃COONa) produces the weak acid (e.g., CH₃COOH)

Formation of Precipitates

• Ions combine to exceed solubility limits—forming an insoluble salt (precipitate)
  • Example: AgNO₃ + NaCl → AgCl↓ + NaNO₃

Formation of Gases

• Ion combination yields a gas (e.g., H₂S, HCN)

Formation of Complex Ions

• Lewis acid (metal) and Lewis base (ligand) react to form a complex
• Ligands bond with the metal atom through coordinate bonds
• Many cations act as metals and form complexes

Redox Reactions

• Redox reactions involve electron transfer
  • Oxidation: loss of electrons
  • Reduction: gain of electrons
• Example: 2 Na(s) + Cl₂(g) → 2 NaCl(s) (Na loses electrons, Cl gains)

Oxidizing and Reducing Agents

• Oxidizing agent: substance that oxidizes another (gets reduced)
• Reducing agent: substance that reduces another (gets oxidized)

Assessment Questions

• Provided multiple examples of different reaction types for calculations and analysis. The questions cover balancing equations, assigning oxidation states, identifying oxidizing/reducing agents, as well as reaction type determination.