Chemical Bonding
Electrochemistry

Chemical Bonding


Overview

 

* Covalent bonds are also present in simple molecular structures. However, they are not broken during physical reactions (e.g. boiling, melting)

 

For questions related to Chemical Bonding:

  1. Determine the type of substance (metal/ ionic/ covalent) and structure (giant metallic/ giant ionic/ giant covalent/ simple molecular) [learn how]
  2. Focus on that particular column to determine the bonding and factors that affect it.

Students tend to make mistakes when they try to pinpoint a factor without regards for the structure and bonding.

 

Simple Molecular Structure

 

To compare strength of intermolecular forces for two molecules:

  1. Check molar mass (Mr): larger Mr → larger e– cloud → more easily polarised → more extensive dispersion
  2. For molecules with similar Mr, check type of molecules (polar/ non polar) [learn how]

There are three possible cases:

 

Case 1 (both polar):

  • Check for H-bonding: molecule with H-bonding will have higher bp/mp.
  • If both have H-bonding, compare the extent of H-bonding i.e. no. of possible H-bond per molecule, presence of intra H-bonding that leads to less extensive inter H-bonding.

Case 2 (one polar, one non-polar):

  • The polar molecule will always have higher bp/mp.
  • pd-pd interactions stronger than dispersion.

Case 3 (both non-polar):

  • Difference must be due to surface area.
  • Increased branching → more spherical e– cloud → lesser area of interaction → less extensive dispersion




- Alkanes (overview)
Structure & Bonding saturated: all C atoms are bonded to 4 atoms all C atom are sp3 hybridised non-polar simple molecular structures consisting of alkane molecules held together by weak VDW forces ...

- Alkenes (overview)
← Back to Alkenes   Structure & Bonding unsaturated: contain C=C C atoms in C=C are sp2 hybridised non-polar simple molecular structures consisting of alkene molecules held together by weak VDW forces ...

- Chemical Bonding
NOTES:   TYPES OF QUESTIONS: Determine Structure and Bonding Draw Dot-Cross Diagrams Determine Type of Bonding for Simple Molecules Predict/ Account for Physical Properties  ...

- Determine Type Of Bonding For Simple Molecules
← Back to Chemical Bonding  To determine the type of molecule (polar/ non-polar) and IMF, you will need these four steps:     1) Draw dot-cross diagram:   1 Determine the central atom and surrounding atoms. Central...

- Determine Structure & Bonding
← Back to Chemical Bonding   Determine Structure:   Structure Metals Giant Ionic Lattice Ionic Compounds Giant Ionic Lattice Covalent Compounds Giant/ Simple Molecule Structure   Metal and Non-Metals...



Electrochemistry








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