Structure Problems: Draw Lewis & Line Structures

In these problems you will be asked to draw chemical structures, interconverting between Lewis structures and line structures and drawing the full line structures corresponding to ones that contain abbreviations. This section is new; if you find issues or errors please leave a comment.

The fact that the properties of substances are related to their structures at the atomic/molecular level has been called the "central dogma" of chemistry.  It follows that being able to interpret and draw representations of chemical structures is a prerequisite to understanding the reactivity of organic compounds.

Chemists use a variety of models, of varying sophistication, to represent molecular structure.  For example, computer-generated 3D models (1 above) are used to provide 'realistic' images of molecules.  Much simpler symbolic representations, such as 'Lewis dot structures' (2), 'Lewis structures' (3) (aka 'Kekule structures') and 'line structures' (4) (aka 'line-bond' or 'skeletal' structures), are easy to draw, and they are routinely used to convey the essential features of molecular structures.  Another commonly used style is 'condensed' (CH₃CH₂OH), and abbreviations are also widely used (EtOH = CH₃CH₂OH).

Because they are easiest to draw, line structures (4), sometimes with condensed parts and/or abbreviations, and sometimes with the addition of lone pairs (double dots), are the most widely used.  However, the omission of C-H bonds in line structures (4) means that it is easy to make mistakes when using them, so understanding what they mean is very important for students of organic chemistry.

The problems on this page will test your understanding of what Lewis structures and line structures represent, your ability to switch between these representations, and your knowledge of the abbreviations used in structures.