Stoichiometry Notes

Stoichiometry Notes

Definition

  • Stoichiometry: The branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions.

Key Concepts

Mole

  • Mole: A unit that measures the amount of substance.

    • 1 mole = 6.022 x 10²³ particles (Avogadro's number).

Chemical Equations

  • Balanced Chemical Equation: Represents the conservation of mass where the number of atoms for each element is the same on both sides.

    • Example: [ \text{2H}_2 + \text{O}_2 \rightarrow \text{2H}_2\text{O} ]

Mole Ratios

  • Mole Ratio: Derived from the coefficients of a balanced equation, used to convert between moles of reactants and products.

    • Example: From the equation above, the mole ratio of H₂ to O₂ is 2:1.

Calculating Moles

  • Formula: [ \text{Moles} = \frac{\text{Mass (g){\text{Molar Mass (g/mol) ]

Limiting Reactant

  • Limiting Reactant: The reactant that is completely consumed in a reaction, limiting the amount of product formed.

  • Identifying: Calculate the moles of each reactant and use mole ratios to determine which reactant runs out first.

Theoretical Yield

  • Theoretical Yield: The maximum amount of product that can be formed from given amounts of reactants, based on stoichiometric calculations.

Actual Yield

  • Actual Yield: The amount of product actually obtained from a reaction.

  • Percent Yield: [ \text{Percent Yield} = \left( \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \right) \times 100 ]

Steps for Stoichiometric Calculations

  1. Write and Balance the Chemical Equation.

  2. Convert Given Information to Moles.

  3. Use Mole Ratios to Find Moles of Desired Substance.

  4. Convert Moles Back to Desired Units (if necessary).

Applications

  • Used in various fields such as pharmaceuticals, environmental science, and materials science to predict quantities of substances involved in reactions.

Common