Measuring Reactions: Stoichiometry & Mole Concept
Stoichiometry and the mole concept focus on understanding quantitative relationships in chemical reactions, using the mole to calculate amounts of reactants and products, enabling precise predictions in chemistry. The mole represents a specific number of particles (Avogadro’s number), allowing conversions between mass, moles, and molecules, which helps determine how much of a substance is needed or produced in a reaction, crucial for experiments and industrial applications.
Overview of Stoichiometry & Mole Concept
Stoichiometry and the mole concept are built on key principles for quantifying chemical reactions. Here’s the breakdown:
- Mole Concept: A mole is 6.022 × 10²³ particles, used to measure amounts of substances.
- Molar Mass: The mass of one mole of a substance, in grams per mole (g/mol).
- Stoichiometric Ratios: Ratios from balanced equations to determine reactant-product relationships.
- Calculations: Using moles, molar mass, and ratios to find amounts of reactants or products.
Lists of Stoichiometry & Mole Concept Components with Examples
Mole Concept Examples
- 1 mole of H₂O contains 6.022 × 10²³ water molecules.
- 0.5 moles of CO₂ equals 3.011 × 10²³ carbon dioxide molecules.
- 2 moles of NaCl represent 1.204 × 10²⁴ formula units of salt.
Molar Mass Examples
- Molar mass of H₂O: 18 g/mol (2H + 1O = 2×1 + 16).
- Molar mass of CO₂: 44 g/mol (1C + 2O = 12 + 2×16).
- Molar mass of NaCl: 58.5 g/mol (1Na + 1Cl = 23 + 35.5).
Stoichiometric Ratios Examples
- For 2H₂ + O₂ → 2H₂O, the ratio of H₂ to H₂O is 2:2 (or 1:1).
- In N₂ + 3H₂ → 2NH₃, the ratio of H₂ to NH₃ is 3:2.
- For CH₄ + 2O₂ → CO₂ + 2H₂O, the ratio of CH₄ to CO₂ is 1:1.
Calculations Examples
- For 2H₂ + O₂ → 2H₂O, 4 moles of H₂ produce 4 moles of H₂O (1:1 ratio).
- In N₂ + 3H₂ → 2NH₃, 6 moles of H₂ yield 4 moles of NH₃ (3:2 ratio).
- For 44 g of CO₂ (1 mole, 44 g/mol), 2H₂ + O₂ → 2H₂O requires 2 moles of H₂ (4 g).