Aha! Chemistry with Prof Bob
  • HOME
    • TALK WITH PROF BOB?
  • LEARNING MODULES
    • Chapter 02 Stuff, matter: What is it? >
      • 0200 Stuff, matter: A theory of atoms
      • 0201 Atoms: The building blocks of all stuff
      • 0202 People classifying stuffs. Why?
    • Chapter 05 Chemical reactions and chemical equations >
      • 0500 Chemical reactions and chemical equations. Overview
      • 0501 Chemical amount and its unit of measurement, mole
      • 0502 The Avogadro constant: How many is that?
      • 0503 The Avogadro constant: Why is it that number?
      • 0504 Chemical formulas: What can they tell us??
      • 0505 Chemical equations: What can they tell us?
      • 0506 Limiting reactants: How much reaction can happen?
      • 0507 Balanced chemical equations: What are they?
      • 0508 Chemical reactions as competitions
    • Chapter 09 Aqueous solutions >
      • 0901 What is a solution? And what is not?
      • 0902 Miscibility of liquids in each other
      • 0903 Like dissolves like? Shades of grey
      • 0905 Dissolution of ionic salts in water: A competition
      • 0906 Can we predict solubilities of salts?
      • 0907 Solution concentration
      • 0908 Chemical species, speciation in aqueous solution
      • 0909 Solutes: Electrolytes or non-electrolytes?
      • 0910 Electrolytes - strong or weak?
      • 0911 Concentrated, dilute, strong, weak
      • 0912 Species concentration vs. solution concentration
      • 0913 Weak electrolytes: Getting quantitative
    • Chapter 11: Dynamic chemical equilibrium >
      • 1100 Dynamic chemical equilibrium: Overview
      • 1101 Visualising dynamic chemical equilibrium
      • 1102 The jargon of chemical equilibrium
      • 1103 Equilibrium constants: The law of equilibrium
      • 1104 The law of equilibrium: an analogy
    • Chapter 22 Evidence from spectroscopy >
      • 2200 Spectroscopy: Overview and preview
      • 2201 Quantisation of forms of energy
      • 2202 Light: Wave-particle "duality"
      • 2203 Ultraviolet-visible spectroscopy
      • 2204 Beer’s law: How much light is transmitted?
    • ENVIRONMENTAL CHEMISTRY >
      • EARTH'S ATMOSPHERE >
        • Chapter 27 The greenhouse effect, climate change >
          • 2700 The greenhouse effect: overview
          • 2701 Is Earth in energy balance?
          • 2702 CO2 in the atmosphere before 1800
          • 2703 So little CO2! Pffft?
          • 2704 Does CO2 affect Earth's energy balance?
          • 2705 The "greenhouse effect"
          • 2706 Why does CO2 absorb radiation from Earth?
          • 2707 The "enhanced greenhouse effect"
          • 2708 Why doesn't CO2 absorb the radiation from the sun?
          • 2709 Why are N2 and O2 not greenhouse gases?
          • 2710 Doesn't water vapour absorb all the IR?
          • 2711 Carbon dioxide from our cars
          • 2712 The source of energy from combustion
          • 2713 Comparing fuels as energy sources
          • 2714 Methane: How does it compare as a GHG?
          • 2715 Different sorts of pollution of the atmosphere
          • 2716 "Acidification" of seawater
      • FUELS
      • EARTH'S OCEANS AND WATERWAYS
  • TEACHERS' CORNER
    • TC01 Language and meaning in chemistry >
      • TC0101 The jargon we use
    • TC02 REPRESENTATION IN CHEMISTRY
    • TC03 MODELLING IN CHEMISTRY
    • TC04 KNOWING AND LEARNING
    • TC05 Communicating chemistry >
      • TC0501 Overview, preview
    • TC06 COMPLEXITY of LEARNING CHEMISTRY
    • TC07 PEDAGOGOICAL CONTENT KNOWLEDGE, PCK >
      • TC0701 Amnesia of the chemistry teaching professioN
    • MODULE-SPECIFIC PCK >
      • Chapter PCK11 Dynamic chemical equilibrium >
        • PCK1101 Visusalizing dynamic chemical equilibrium
        • PCK1103 Equilibrium constants: The law of equilibrium
      • Chapter PCK22 Evidence from spectroscopy >
        • PCK2204 Beer's law
  • NAVIGATION
    • Table of contents
    • Index, alphabetical

Chapter 11-specific PCK

PCK1101

Visualising dynamic chemical equilibrium

With reference to Learning module 1101: Visualising dynamic chemical equilibrium
I am committed to the belief that good quality visualization at the molecular level of chemical phenomena is a crucial component of meaningful understanding in chemistry.

The cultivation of quality imagery in our students presents a massive challenge. First, there is the question of what constitutes good visual imagery for a particular phenomenon, because I almost find that other people’s images are different in some way from mine.

And then there is the pedagogical challenge of how to develop good quality images of the nature and behaviour of atoms, ions and molecules.

We all use words to describe phenomena, but oh to be able to see what mental images those words conjure up.
You are rambling, Prof Bob …..


Well, where I am going is that I find it difficult to visualize reactions in a reaction mixture proceeding simultaneously in the “forward” and “backward” directions. I know what it means, but I have trouble with a mental picture.

Things are much easier for me when I refer (defer?) to my view that all chemical reactions are the result of competitive processes: acid-base reactions are competition for protons; oxidation-reduction reactions are competition for electrons; complexation reactions competition for ligands.

Now the world opens up for me!

I can well imagine that in an aqueous solution of acetic acid, water molecules are continuously “winning” protons from aquated acetic acid molecules, and that simultaneously aquated acetate ions are “winning” protons from hydroniums ions.

Yes, it is easy for me to imagine protons being “grabbed” and being pulled from one species to another. Hence the analogy that I use in module 1101: Visualizing dynamic chemical equilibrium.

Yes, I am aware that proton transfer is (or results in) the reaction represented by the written chemical equation.
But it helps me to see it that way. Maybe some students will, also?
​
Finding your way around .....

You can browse or search the Aha! Learning chemistry website in the following ways:
  • Use the drop-down menus from the buttons at the top of each page to browse the modules chapter-by-chapter.
  • Click to go to the TABLE OF CONTENTS (also from the NAVIGATION button) to see all available chapters and modules in numbered sequence.
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LEARNING CHEMISTRY FOR UNDERSTANDING

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  • HOME
    • TALK WITH PROF BOB?
  • LEARNING MODULES
    • Chapter 02 Stuff, matter: What is it? >
      • 0200 Stuff, matter: A theory of atoms
      • 0201 Atoms: The building blocks of all stuff
      • 0202 People classifying stuffs. Why?
    • Chapter 05 Chemical reactions and chemical equations >
      • 0500 Chemical reactions and chemical equations. Overview
      • 0501 Chemical amount and its unit of measurement, mole
      • 0502 The Avogadro constant: How many is that?
      • 0503 The Avogadro constant: Why is it that number?
      • 0504 Chemical formulas: What can they tell us??
      • 0505 Chemical equations: What can they tell us?
      • 0506 Limiting reactants: How much reaction can happen?
      • 0507 Balanced chemical equations: What are they?
      • 0508 Chemical reactions as competitions
    • Chapter 09 Aqueous solutions >
      • 0901 What is a solution? And what is not?
      • 0902 Miscibility of liquids in each other
      • 0903 Like dissolves like? Shades of grey
      • 0905 Dissolution of ionic salts in water: A competition
      • 0906 Can we predict solubilities of salts?
      • 0907 Solution concentration
      • 0908 Chemical species, speciation in aqueous solution
      • 0909 Solutes: Electrolytes or non-electrolytes?
      • 0910 Electrolytes - strong or weak?
      • 0911 Concentrated, dilute, strong, weak
      • 0912 Species concentration vs. solution concentration
      • 0913 Weak electrolytes: Getting quantitative
    • Chapter 11: Dynamic chemical equilibrium >
      • 1100 Dynamic chemical equilibrium: Overview
      • 1101 Visualising dynamic chemical equilibrium
      • 1102 The jargon of chemical equilibrium
      • 1103 Equilibrium constants: The law of equilibrium
      • 1104 The law of equilibrium: an analogy
    • Chapter 22 Evidence from spectroscopy >
      • 2200 Spectroscopy: Overview and preview
      • 2201 Quantisation of forms of energy
      • 2202 Light: Wave-particle "duality"
      • 2203 Ultraviolet-visible spectroscopy
      • 2204 Beer’s law: How much light is transmitted?
    • ENVIRONMENTAL CHEMISTRY >
      • EARTH'S ATMOSPHERE >
        • Chapter 27 The greenhouse effect, climate change >
          • 2700 The greenhouse effect: overview
          • 2701 Is Earth in energy balance?
          • 2702 CO2 in the atmosphere before 1800
          • 2703 So little CO2! Pffft?
          • 2704 Does CO2 affect Earth's energy balance?
          • 2705 The "greenhouse effect"
          • 2706 Why does CO2 absorb radiation from Earth?
          • 2707 The "enhanced greenhouse effect"
          • 2708 Why doesn't CO2 absorb the radiation from the sun?
          • 2709 Why are N2 and O2 not greenhouse gases?
          • 2710 Doesn't water vapour absorb all the IR?
          • 2711 Carbon dioxide from our cars
          • 2712 The source of energy from combustion
          • 2713 Comparing fuels as energy sources
          • 2714 Methane: How does it compare as a GHG?
          • 2715 Different sorts of pollution of the atmosphere
          • 2716 "Acidification" of seawater
      • FUELS
      • EARTH'S OCEANS AND WATERWAYS
  • TEACHERS' CORNER
    • TC01 Language and meaning in chemistry >
      • TC0101 The jargon we use
    • TC02 REPRESENTATION IN CHEMISTRY
    • TC03 MODELLING IN CHEMISTRY
    • TC04 KNOWING AND LEARNING
    • TC05 Communicating chemistry >
      • TC0501 Overview, preview
    • TC06 COMPLEXITY of LEARNING CHEMISTRY
    • TC07 PEDAGOGOICAL CONTENT KNOWLEDGE, PCK >
      • TC0701 Amnesia of the chemistry teaching professioN
    • MODULE-SPECIFIC PCK >
      • Chapter PCK11 Dynamic chemical equilibrium >
        • PCK1101 Visusalizing dynamic chemical equilibrium
        • PCK1103 Equilibrium constants: The law of equilibrium
      • Chapter PCK22 Evidence from spectroscopy >
        • PCK2204 Beer's law
  • NAVIGATION
    • Table of contents
    • Index, alphabetical