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Thermochemical Changes Unit 2016
Page 1: Archibishop O'Leary High School Chemistry 30 Thermochemical Changes Unit
Equipment used in experiments
Motorized stirrer
Electrical leads for igniting samples
Thermometer
Insulated container
O2 inlet
Bomb (reaction chamber)
Fine wire in contact with sample
Cup holding sample
Water
Page 2: Perspectives on STS Issues
Various perspectives on Science-Technology-Society (STS) issues:
Scientific Perspective: Research and explanations of natural phenomena; e.g., sources and effects of air pollution.
Technological Perspective: Development of machines/instruments for social purposes; e.g., measuring and preventing air pollution.
Ecological Perspective: Relationships between living organisms and environment; e.g., effects of emissions on plants, animals, and humans.
Economic Perspective: Focus on wealth production, distribution, and consumption; e.g., costs of preventing and repairing pollution damages.
Political Perspective: Government actions and legislation regarding issues; e.g., proposals to control air pollution.
Page 3: Evaluating Perspectives on Statements
Example 1: Statement about fossil fuels and global warming; possible perspectives to consider:
a) Scientific
b) Political
c) Economic
d) Ecological
Page 4: Unit A: Thermochemical Changes
Chemical reactions involve energy changes crucial for life on Earth.
Photosynthesis: Energy from the sun converted to chemical energy in carbohydrates.
Animals use stored energy via cellular respiration to generate heat and support growth/movement.
After organic matter decay, hydrocarbons transform into fossil fuels powering modern society.
Thermodynamics: Study of energy transfer and changes.
Thermochemistry: Focus on energy changes in physical and chemical processes.
Page 5: Photosynthesis Process Completes
During photosynthesis:
Energy from the Sun (i) is converted to Chemical energy (ii).
Possible answers:
A: Sun, Light
B: Sun, Chemical
C: Plant, Light
D: Plant, Chemical
Page 6: Types of Energy
Energy: Ability to do work.
Types:
Kinetic: Energy of motion.
Potential: Stored energy.
Discussed Properties:
Temperature: Involves intermolecular (between molecules) and intramolecular (within molecules) changes.
Heat: Transfer of thermal energy.
Page 7: Kinetic Energy (EK)
Energy of motion; especially of particles (thermal energy).
Kinetic Molecular Theory: Smallest substance particles are in continuous motion.
Types of particle motion:
Translational Motion: Straight line motion.
Rotational Motion: Spinning motion.
Vibrational Motion: Oscillating motion.
Page 8: States of Matter & Their Properties
Solids:
Definite shape & volume
Limited rotational and vibrational motion
Liquids:
Shape of container, definite volume
Moderate movement of particles
Gases:
Assume shape & volume of container
High particle movement & compressibility
Page 9: Energy Changes in Reactions
Example: Methane combustion equation and motion changes resulting from the reaction:
Decrease in the molecules’ movements/translational motion, calculated via motion types.
Page 10: Heat vs. Temperature
Temperature: Measure of average kinetic energy of molecules; changes with energy transfer.
Factors influencing temperature change:
Quantity of heat transfer
Amount of substance present
Specific heat capacity
Units for heat: Joule (J); Kilojoule (kJ) when > 1000 J.
Definitions:
Specific Heat Capacity: Heat required to raise temperature.
Volumetric Heat Capacity: Heat needed to raise temperature for liquids.
Page 11: Heat Transfer Calculations
Heat flow calculations with the formula: q = mc∆t or q = vc∆t.
Examples of heat calculations for various scenarios including heating water and energy transfer with specific heat specifications about different materials.
Page 12: Heat Calculations for Water
Example calculations on quantities of heat for heating water:
From 22.0°C to 98.0°C.
Released heat from cooling soft drink from 22.0°C to 10.0°C.
Page 13: Specific Calculations involving Aluminum and Coolant
Absorbing heat calculations in different systems (aluminum and coolant) for engines with defined temperature changes.
Page 14: Heat Flow in Liquid Systems
Laboratory measurements on heat flow in liquid solutions; specific calculations for specific heat capacity and temperature adjustments related to human body heat loss A.
Page 15: Energy Changes in Chemical Bonds
Potential Energy (EP): Stored energy in chemical bonds; involved in thermal energy changes during reactions.
Bonds broken require energy (endothermic), bonds formed release energy (exothermic).
Page 16: Potential Energy Diagram for Endothermic Changes
Diagrams represent energy levels before and after reactions; endothermic changes where products have more energy than reactants.
Page 17: Bond Energy in Reactions
Bond energy: energy needed to break a bond;
Endothermic Reactions: More energy absorbed than released.
Page 18: Overview of Exothermic Reactions
Release energy in the form of heat, leads to temperature increases in surroundings; products have less energy than reactants in exothermic reactions.
Page 19: Examples of Exothermic Reaction Calculations
Analyzing energy shifts during reactions and examples illustrating changes.
Page 20: Potential Energy Diagrams for Reaction Types
Diagrams showcasing energy changes for combustion and decomposition reactions in an educational context.
Page 21: Energy Changes in Reactions
Evaluating diagrams and their relation to enthalpy change in various reactions.
Page 22: Energy Changes and Enthalpy Relation
Enthalpy change definitions and symbols detailing how heat absorption or release occurs based on the reaction results.
Page 23: Calculating Enthalpy Changes
Formula and methods to calculate enthalpy associated with solutions and key guidelines regarding signs for energy changes during reactions.
Page 24: Example Molar Enthalpy Calculations
Evaluating combustion scenarios through enthalpy calculations to determine heat of reaction based on mass and heat values.
Page 25: Simple Calorimetry Concept
Basics of calorimetry experiments; constructing instruments to measure energy changes with basic principles in energy conservation.
Page 26: Example Calorimetry Calculation
Specific ethanol combustion measured by water temperature changes within calorimetric setup.
Page 27: Data Collection in Calorimetry
Required data needed to determine molar enthalpy across experiments.
Page 28: Enthalpy of Reaction Analysis
Systematic exploration of methanol combustion's requirements through heat calculations across chemical responses.
Page 29: Neutralization Enthalpy Calculation
Calculation of specific heat transfers for neutralization reactions and overall evaluation of combustion heats.
Page 30: Ethanol Combustion Calculations
Determining molar enthalpy throughout experimental scenarios using water heating examples.
Page 31: Bomb Calorimeter Overview (Optional)
Bomb calorimeter precision & its use in measuring combustion reactions with a focus on energy calculations and their representation.
Page 32: Heat Calculation from Bomb Calorimeter
Using heat capacity equations for studying reactions to find molar enthalpy through specific example applications.
Page 33: Energy to Mass Ratio Concept
Determining the energy transfer per gram utilizing calorimetry setups in studies using modified equations expressing energy outputs.
Page 34: Reaction Enthalpies in Chemical Processes
Understanding enthalpy changes in reactions and how to represent them quantitatively with multiple chemical systems.
Page 35: Enthalpy Changes for Reactions
Evaluation of calculated enthalpy changes related to particular chemical equations and molar definitions.
Page 36: Energy Changes in Balanced Equations
How to include energy factors directly into chemical equations for clarity in reaction enthalpies.
Page 37: Potential Energy Diagrams for Various Reactions
Visual representation of energy shifts in reaction types to correlate with thermodynamic principles.
Page 38: Visualizing Potential Energy Changes
Overview of potential energy diagrams to demonstrate different thermodynamic conditions throughout reactions.
Page 39: Communicating Energy Changes
Methods to illustrate thermochemical properties and their diverse applications across biological and physical systems.
Page 40: Communicating Thermochemical Equations
Examples of how to rewrite chemical equations to demonstrate energy changes.
Page 41: Balanced Chemical Equations with Enthalpy Changes
Guidelines for how to include enthalpy changes within chemical reaction visuals to enhance communicative effectiveness.
Page 42: Hess's Law Overview
Defining Hess's Law for energy change calculations through systematic summation of enthalpies from chemical reactions.
Page 43: Application of Hess's Law in Molar Enthalpy Calculations
Practical methodology for using Hess’s Law; engaging practical examples understanding enthalpy transfers across multiple reactions.
Page 44: Steps in Hess's Law Application
Procedural evaluation on how to conduct multiple steps involved in energy change analysis through summation of enthalpy changes.
Page 45: Example Enthalpy Calculations through Hess's Law
Determining enthalpies resultant from combining curative steps of reaction analysis process.
Page 46: Predicting using Hess’s Law
Application through predictive examples illustrating enthalpy changes under varying synthesis conditions.
Page 47: In-depth Exploration of Reaction Energies
Analyzing energy release across different systems along with predicted heat changes during combustion.
Page 48: Predicting Molar Enthalpy Changes
Methods for assessing molar heats of formation while showcasing some valuable theoretical approaches.
Page 49: Applications of Molar Heats of Formation
Practical applications detailing efficiency and relationship of energy transfer dynamics within known reaction conditions.
Page 50: Potential Impacts of Carbohydrate Reactions
Discussing oxidation reactions relevant to human metabolism with comparative analysis between combustion and photosynthesis.
Page 51: Evaluative Techniques in Chemical Reactions
Analytical methods used to gauge heat outputs for specific reactions detailing efficiency within renewable sources.
Page 52: Predicting Molar Enthalpy Changes from Reaction Evidence
Analyzing standard conditions and determining the molar enthalpy of reactions through practical experimentation.
Page 53: Laboratory Standardizations in Enthalpy Applications
Flow of enthalpy changes across various applications focusing on calculated adjustments adjusted for the reaction scale.
Page 54: Finding Standard Enthalpy Calculations
Practical assessments determining enthalpy changes from varied reactions through the combined energy perspectives to foster understanding.
Page 55: Thermal Stability as a Measure of Compound Strength
Investigating the correlation between energy requirements and bond stability; practical demonstrations reflected through compound examples.
Page 56: Assessing Thermal Stability through Reaction Types
Analyzing stability within halide and non-halide compounds establishing predictive stability relationships based on empirical data.
Page 57: Multi-Step Energy Calculations Process
Outline procedural factors necessary to systematically evaluate complex chemical reactions through energy changes.
Page 58: Predicting Energy Changes in Chemical Reactions
Examination on how energy shifts play a role during combustion reactions focusing on practical implications.
Page 59: Energy Released During Reaction Analysis
Real-world scenarios showcasing the energy outputs and associated reactions offering tangible insights into direct applications.
Page 60: Energy Release in Combustion and Applications
Investigation into direct applications of combustion processes in regards to the energetic output of various substances.
Page 61: Measuring Efficiency and Output Energy Change
Demonstrating relationship factors that detail energy transfers in physical processes enhancing understanding of heat measurement practices.
Page 62: Understanding Activation Energy in Reactions
Overview of activation energy concepts providing insights into the necessary conditions for reactions to occur effectively.
Page 63: Assessing Energy Barriers in Reactions
Evaluation of how reactants must overcome specific energy barriers determined through empirical reaction pathways.
Page 64: Visual Representations of Activation Energy
Diagrams focusing on potential energy variations across reactions enriching comprehension of catalytic effects.
Page 65: Potential Energy Diagrams Demonstrating Reaction Sequence
Detailed pathway evaluations that demonstrate potential energy shifts through chemical reaction progress.
Page 66: Evaluating Energy Barriers in Reactions
Systematic assessment of reaction diagrams highlighting energy barriers through different conditions.
Page 67: Analyzing Catalyst Functions in Reactions
Understanding catalyst roles within chemical reactions providing insight into mechanism efficiencies within varied applications.
Page 68: Introduction to Biological Catalysts
Focusing on enzymes as catalysts detailing their functions and situational requirements necessary for effective reaction uptakes.
Page 69: Summary of Catalysts in Chemistry
Broad overview of catalyst functionalities within various industries portraying their importance and effectiveness.
Page 70: Efficiency and Energy Reduction Perspectives
Discussing efficiency methodologies along with their recognized impacts within energy consumption systems and efficiency evaluations.
Archibishop O'Leary High School Chemistry 30 Thermochemical Changes Unit
Equipment Used in Experiments:
Motorized stirrer
Electrical leads for igniting samples
Thermometer
Insulated container
O2 inlet
Bomb (reaction chamber)
Fine wire in contact with sample
Cup holding sample
Water
Perspectives on STS Issues:
Scientific: Research on natural phenomena; e.g., air pollution sources & effects.
Technological: Development of instruments for social purposes; e.g., air pollution measurement/prevention.
Ecological: Relationships between organisms and environment; e.g., emissions effect.
Economic: Focus on wealth production, distribution, consumption; e.g., pollution cost prevention/repair.
Political: Government actions and legislation; e.g., control proposals for air pollution.
Thermochemical Changes:
Energy changes are crucial in chemical reactions.
Photosynthesis: Converts solar energy to chemical energy.
Thermodynamics: Study of energy transfer; Thermochemistry: Focused on energy changes in physical and chemical processes.
Energy Types:
Kinetic: Energy of motion.
Potential: Stored energy.
States of Matter:**
Solids: Definite shape & volume.
Liquids: Shape of container, definite volume.
Gases: Take shape & volume of container.
Heat Transfer Calculations:
Formulae:
q = mc∆torq = vc∆tas methods for calculating heat flow.
Enthalpy Changes:
Endothermic: Absorb more energy than released; products have more energy than reactants.
Exothermic: Release energy as heat; products have less energy than reactants.
Calculation methods outlined for determining enthalpy of reactions using Hess’s Law and calorimetry.
Catalysts:**
Enzymes and catalytic roles in driving reaction efficiency.
NoteStudied by 100 peopleNoteStudied by 56 peopleNoteStudied by 9 peopleNoteStudied by 1 personNoteStudied by 23 peopleNoteStudied by 46 people