Ch. 1 - A Review of General ChemistrySee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

What if you want to describe a molecule, but you have nothing but a keyboard? (No fancy pictures or drawings). This is was actually a big dilemma in the chemistry world, which is why we now have condensed structure. 

Condensed Rules

Concept #1: How to interpret condensed structures.

The condensed structure shows us the connectivity of the molecule. The use of parentheses is important:

  • Parentheses with no subscripts: Branch on the chain.
  • Parenthesis with subscripts: Multiple branches on a chain.
  • CH2 within parentheses + subscripts: Repeating CH2 units within a chain.
Condensed Mixed Structures

Example #1: How to draw condensed mixed structures.

This is similar to normal condensed structure, except there is a bondline ringed component. Always draw your condensed letters in terms of connectivity!

  • If to the right of the ring: Draw branch normally.
  • If to the left of the ring: Draw branch in reverse.  

Practice: Convert the condensed structure into a bondline structure 

Remember, the exact direction of your zig-zag pattern doesn’t matter as long as everything is connected correctly. Single bonds can rotate freely, so let’s not spend lots of time worrying about the exact angles you drew.

Additional Problems
Draw a bond-line structure for each of the following compounds: 
Draw a bond-line structure for each of the following compounds: 
Draw a bond-line structure for each of the following compounds: 
Draw a bond-line structure for each of the following compounds: 
Draw a bond-line structure for each of the following compounds: 
Draw a bond-line structure for each of the following compounds: 
Expand the following structural representations so as to more clearly show all the atoms and any unshared electron pairs. What are their molecular formulas? Are any of them isomers? 
Which formula is equivalent to the condensed formula (CH 3)3C(CH2)2CH3?
Consider a molecule with the following condensed formula: CHO(CH2)2COCH2NH(CH3) Construct a dash structural formula for the compound above. Include all nonbonding electron pairs and hydrogen atoms.
Write a condensed structural formula for each compound given here.
Write a condensed structural formula for each compound given here.
Write a condensed structural formula for each compound given here.
Write a condensed structural formula for each compound given here.
What is the molecular formula for each of the compounds given in Exercise 1.33?
What is the molecular formula for each of the compounds given in Exercise 1.33?
What is the molecular formula for each of the compounds given in Exercise 1.33?
Write the condensed formula of the following molecule:
Rewrite each of the following using bond-line formulas:
Rewrite each of the following using bond-line formulas:
Rewrite each of the following using bond-line formulas:
Draw the line-angle structures of the following molecules a) (CH3)2CHCOCH(CH3)2 b) CH3CO2H
Convert the following condensed molecular formulas into bondline (line-angle) form. CH3CH2CH=CHCHOH(CH2)3CH(CH2CH3)CH2CO2H
What is the  total number of pi (π) bonds  present within the octet structure of (CH3O)3PO? A. 0 B. 1 C. 2 D. 3 E. 4 F. More than 5
There are at minimum 4 different ways to draw the structure of Butane:  Lewis Dot, Structural, Skeletal, and Condensed. Put your drawing skills to the test by showing them below. 
Convert the following skeletal structure into condensed:
Convert the following condensed structure into Lewis:
Convert the following condensed formula into a Lewis structure (including all lone pair electrons). CH3CONHCH3
Draw the expanded structural formula for the following condensed formula. (Draw all hydrogen atoms.) CH3CH(CH3)CH2CHO 
Write the condensed structure for the following structure.  
Write a condensed structural formula for each molecule. 
Write a condensed structural formula for the following molecule:
Draw the condensed structural formulas for the products of the following.  
Draw the correct bond-line structure for the following compound.
Draw the correct bond-line structure for the following compound: CH 2=CHCH2(CH3)3
Draw the correct bond-line structure for the following compound: CH2=CHOCH2CH(CH3)2 
Write the condensed structure for the following structure.