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

Since we are going to be drawing A LOT of molecules over the next year, it makes sense to find an easier way to draw them. Hence, I now present to you :::drumroll::: the skeletal structure!

*Also known as bondline structure or line-angle structure. 

Things You Don't Have to Draw
  • Carbons are implied: Every corner is assumed to represent a carbon.
  • Hydrogens are implied: Carbon is assumed to possess enough hydrogens to fill its octets.
  • Lone Pairs are implied: Heteroatoms are assumed to possess enough electrons to fill their octets.
  • Formal Charges are used to indicate when an atom does not satisfy its bonding preference.

Watch Out: ALL hydrogens on heteroatoms MUST be drawn explicitly. 

Concept #1: How bondline is different from Lewis Structures.

Example #1: Conversion of ethanol from electron dot to bondline

Practice: How many implied hydrogens does each labeled carbon have? 

Practice: How many implied hydrogens does each labeled carbon have? 

Practice: Convert the structure into a line-angle structure. Be sure to assign ALL necessary formal and net charges.

Practice: Convert the structure into a line-angle structure. Be sure to assign ALL necessary formal and net charges.

Practice: Convert the structure into a line-angle structure. Be sure to assign ALL necessary formal and net charges.

 

Hint: Remember that you need to include formal charges if atoms are not at their bond preference. 

Practice: Convert the structure into a line-angle structure. Be sure to assign ALL necessary formal and net charges.

We’ll be drawing these for the rest of the semester. Hope you liking them so far!

Additional Problems
Look at the entire structure of Lamisil. How many hydrogen atoms are present in the structure of this molecule? A. 20      E. 24       I. 28 B. 21      F. 25       J. None of these C. 22      G. 26 D. 23      H. 27
CL-20 and HMX are both powerful explosives. CL-20 produces a more powerful blast but is generally considered too shock-sensitive for practical use. HMX is significantly less sensitive and is used as a standard military explosive. When a 2:1 mixture of the two compounds is cocrystallized, the resulting explosive is expected to be more powerful than HMX alone, but with a sensitivity similar to HMX (Cryst. Growth Des. 2012, 12, 4311–4314).  (a) What are the molecular formulas for CL-20 and HMX? 
Ramelteon is a hypnotic agent used in the treatment of insomnia:  (a)  What is the molecular formula of this compound? 
Cycloserine is an antibiotic isolated from the microbe Streptomyces orchidaceous. It is used in conjunction with other drugs for the treatment of tuberculosis.  (a)  What is the molecular formula of this compound? 
What is the molecular formula for each compound in the previous problem?
What is the molecular formula for each compound in the previous problem?
What is the molecular formula for each compound in the previous problem?
Write structural formulas for each of the following: (m) A tertiary amine with the formula C3H9N.
Identify the number of carbon atoms and hydrogen atoms in the compound below:
Look at the  entire structure of Atenolol. What is the  total number of lone pairs present within the structure of this molecule? A. 0 B. 1 C. 2 D. 3 E. 4 F. 5 G. 6 H. 7 I.  8 J. None of these
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? 
Click the "draw structure" button to lunch the drawing utility.Expand the following bond-line formula to show all atoms and bonds.
Write the molecular formula for each of the following. Enter elements in order C H O N X.
Write the molecular formula for each of the following. Enter elements in order C H O N X.
The following bond line structure has a total of _____ hydrogen atoms.
How many carbon atoms are in the molecule below?
Draw the correct bond-line structure for the following compound:
Indicate the molecular formula for each of the following compounds. Enter your answer in form of CxHyOw.
Hexane is an unbranched alkane with the condensed structure CH3CH2CH2CH2CH2CH3. a) Draw the complete structure of hexane. (Show all hydrogen atoms.) b) Draw the skeletal structure of hexane in line-bond (line-angle) mode. (Do not show hydrogen atoms.)
How many hydrogen atoms are bonded to the positively charged carbon?
State the number of hydrogens bonded to each labeled carbon in the following substance and give its molecular formula. a. Hydrogens at carbon a b. Hydrogens at carbon bc. Hydrogens at carbon cThe molecular formula is _____.
In the following reaction, how many H's do you add or lose? Select one:                • Add 1                 • Add 2                • Lose 1                • No change