The molecular world - OpenLearm Reimagined

Content generated from the OpenLearn Unit [The molecular world](https://www.open.edu/openlearn/science-maths-technology/chemistry/the-molecular-world/content-section-0?active-tab=description-tab).

Contents:

SubHeading

• 1 Everything that you can see is made of atoms
  • 1.1 Introduction
  • 1.2 Chemical elements
  • 1.3 Chemical compounds
  • 1.4 Molecular substances
  • 1.5 Non-molecular substances
  • 1.6 Binding forces in molecular and non-molecular substances - a first look
  • 1.7 Summary of Section 1
• 2 Chemical patterns are to be found in the periodic table
  • 2.1 Chemical periodicity
  • 2.2 The Group number of the noble gases
  • 2.3 Elements on parade: an audiovisual interlude
  • 2.4 Summary of Section 2
• 3 Chemistry can often be explained by electronic structure
  • 3.1 Introduction
  • 3.2 The electronic configurations of atoms
  • 3.3 Electronic configurations and the Periodic Table
  • View document
  • 3.4 Outer electronic configurations and the Periodic Table
  • 3.5 Electron states and box diagrams
  • 3.6 Summary of Section 3
• 4 Chemical bonds consist of shared pairs of electrons
  • 4.1 Introduction
  • 4.2 Ionic and covalent bonding
  • 4.3 Metallic bonding
  • 4.4 A classification of chemical substances
  • 4.5 More about covalent bonding
  • 4.6 Summary of Section 4
• 5 Molecular reactivity
  • 5.1 Molecular reactivity is concentrated at key sites
  • 5.2 Summary of Section 5
• 6.1 Introduction
  • Question 34
  • Question 35
• 6.2 The shapes of some molecules
  • Question 36
  • Maths help: equilateral triangles
  • Question 37
  • Question 38
  • Question 39
  • Question 40
• 6.3 Valence-shell electron-pair repulsion theory
  • Question 41
  • Question 42
  • Question 43
  • Question 42
  • Question 43
• 6.4 Summary of Section 6
  • Question 17
  • Question 18
  • Question 19
  • Question 20
  • Question 21
  • Question 22
• 7 Reactivity needs a favourable rate and equilibrium constant
  • 7.1 Introduction
  • 7.2 Is the equilibrium position unfavourable?
  • are taking place: at the microscopic, molecular level there is ceaseless change in both directions. However, at equilibrium, the overall rates of the forward and backward reactions are equal. The reaction system then seems static because, at the macroscopic level where we measure things, there is no apparent change in the amounts or concentrations of any of the four gases involved. Suppose that Reaction 8.1 appears not to occur because, although it has reached equilibrium, the equilibrium position is unfavourable. Then it must be that the rates of the forward and backward reactions become equal when the concentrations of the reactants (NO and CO) are very high, and those of the products (N2 and CO2) are very small, so small as to be undetectable. This possibility can be tested by examining the equilibrium constant, K, for the reaction.
  • 7.3 Is the rate of reaction very slow?
  • 7.4 Equilibrium positions and rates of reaction in this course
  • 7.5 Summary of Section 7
• Conclusion
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