Chemistry Chapter 5 Flashcards

Chemical Reactions

• Reactants and Products: Reactants are positioned on the left, products on the right of a chemical equation.
• Decomposition Reaction: Calcium carbonate (CaCO3) decomposes when heated to form calcium oxide (CaO) and carbon dioxide (CO2).
• Limiting Reactant: The limiting reactant is the substance that is consumed first, halting the reaction.

Balancing Chemical Equations

• Balanced Equation Coefficients: For the equation NaOH + H2S → Na2S + H2O, the coefficients are 2, 1, 1, and 2, respectively.
• Mole Ratios: When balancing KO2 + H2O → KOH + O2, the mole ratio of O2 to KO2 is 3 mol O2/4 mol KO2.

Mole Calculations

• Sulfur Production: From the reaction 16H2S + 8SO2 → 16H2O + 3S8, 0.250 mole of SO2 produces 0.0938 mole of S8.
• Percent Yield of Ethanol Combustion: The combustion of 75.0 g of ethanol gives a percent yield of 67.5% for the production of CO2.
• Moles of Reactants: In the reaction 2K + Br2 → 2KBr, 10.0 moles of potassium require 5.00 moles of bromine.
• Limiting Reactant in a Potassium and Bromine Reaction: In the reaction of 2.00 grams each of potassium and bromine, bromine (Br2) is the limiting reactant.
• Mass Calculation of Potassium Chloride: From 5.2 g of potassium and 7.9 g of chlorine, 9.9 g of potassium chloride (KCl) can be produced.

Reaction Types

• Catalysts: Catalysts lower the activation energy, enhancing the reaction rate.
• Synthesis Reaction: Involves combining multiple elements or compounds to form one complex product (A + B → AB).
• Decomposition Reaction: A single compound breaks down into simpler substances (AB → A + B).
• Single Replacement Reaction: One element replaces another in a compound (A + BC → AC + B).
• Double Replacement Reaction: Elements in two compounds exchange partners (AB + CD → AD + CB).

Redox Reactions

• Reduction: The gain of electrons during a reaction.
• Oxidation: The loss of electrons during a reaction.
• Redox Reactions: These always involve both oxidation and reduction processes and electron transfer.

Stoichiometry

• Stoichiometry: The study of relationships between moles and mass in chemical reactions; coefficients signify the number of moles.
• Limiting and Excess Reagents: The limiting reagent is consumed first, while excess reagents are leftover reactants after the reaction.
• Theoretical Yield: The highest possible quantity of product produced from a given amount of reactants.

Yield and Free Energy

• Actual Yield: The real amount of product obtained from a chemical reaction.
• Free Energy: Energy gained or released in a reaction based on bond breaking and formation.
• Spontaneous Reactions: Occur without ongoing input of energy and have a negative free energy value.
• Nonspontaneous Reactions: Require energy input to proceed and have a positive free energy value.

Reaction Dynamics

• Exothermic Reactions: Release heat energy, common in combustion processes.
• Endothermic Reactions: Absorb energy to proceed, requiring external energy input.
• Reaction Rate: The speed at which products form in a reaction.
• Activation Energy (Eact): The barrier energy necessary to transition from reactants to products; reducing the activation energy increases the reaction rate.
• Factors Affecting Reaction Rate: Changing temperature, concentration, or adding a catalyst can alter the speed of a reaction.

Key Outcomes

• Lowering Activation Energy: Increases reaction rate, facilitating faster product formation.
• Adding Catalysts: Permanently lowers activation energy and accelerates reactions without being consumed.

Test your knowledge of key concepts from Chemistry Chapter 5 with these flashcards. Each card provides definitions and examples related to chemical equations, reactants, products, and reaction types. Perfect for mastering the foundational elements of chemical reactions.