Ch. 2 - Molecular RepresentationsWorksheetSee 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

Only one rule to know here: Like polarity dissolves like polarity

Concept #1: Understanding “like dissolves like”. 

Want a vodka tonic right about now? The reason they mix together is due to similar polarity between molecules. Not that you should know about this if you are under the age of 21! Duh.  

Concept #2: Introducing common solvents and other molecules in organic chemistry. 

An aqueous solution is one with water. That’s pretty much it. The following molecules are commonly used in organic chemistry - so it’s a good idea to know what their solubilities are.

Practice: Would you expect the following molecule to be miscible in an aqueous solution? 

Practice: Would you expect the following molecule to be miscible in an aqueous solution? 

Practice: Would you expect the following molecule to be miscible in an aqueous solution? 

Practice: Would you expect the following molecule to be miscible in an aqueous solution? 

Hint: Draw the Lewis structure before deciding!

Practice: Would you expect the following molecule to be miscible in an aqueous solution? 

Hint: Draw the Lewis structure before deciding!

Practice: Would you expect the following molecule to be miscible in an aqueous solution? 

Additional Problems
(i) Which compound is less soluble in water: (a) CH 3(CH2)4CH2OH or (b) CH3(CH2)3CH2OH? (Choose one; give the letter.) (ii) Which compound is releases less heat when it is burned: (a) CH 3(CH2)4CH3 or (b) (CH3)3CCH2CH3? (Choose one; give the letter.) (iii) Which compound has the higher boiling point: (a) CH 3(CH2)3CH3 or (b) (CH3)2CHCH(CH3)2? (Choose one; give the letter.) (iv) A Lewis base can also be known as (a) an electrophile, (b) a nucleophile, or (c) a spectator ion ? (Choose one; give the letter.) (v) Which one is the most basic: (a) (CH3)3CO− ; (b) CH3CH2O−; or (c) (CH3)2CHO− ? (Choose one; give the letter.) (vi) Which compound is more oxidized: (a) CH3CO2H or (b) HOCH2CH2OH ? (Choose one; give the letter. If they are the same, give both letters.) (vii) Which one is the molecular formula of a neopentyl group: (a) C5H9 ; (b) C5H10; (c) C5H11 ; or (d) C5H12 ? (Choose one; give the letter.) (viii) Which compound is an alcohol that is not miscible with water: (Choose one; give the letter.) (a) CH3CH2OCH3; (b) CH3CH2CH2OH; or (c) CH3CH2CH2CH2OH ? (ix) What type of alkyl group is a 1-methylcyclohexyl group: (a) primary ; (b) secondary ; (c) tertiary ; or (d) quaternary (Choose one; give the letter.)  (x) Which compound is more soluble in water: (i) CH3CH2CH2OH or (ii) CH3CH2CH2Cl? (Choose one; give the letter.)  
Which compound is more soluble in water? a) CH3(CH2)2CH2OH or b) CH3(CH2)2CH3
Select the compound that is soluble in water and explain why.  
Select the molecule with greater solubility in water. Provide a brief explanation. Propanoic acid or Decanoic acid
Cetylethyldimethylammonium bromide is the common name for a compound with antiseptic properties. Predict its solubility behavior in water and in diethyl ether.
Which of the following solvents should be capable of dissolving ionic compounds? a. Liquid SO2 b. Liquid NH3 c. Benzene d. CCl4
For each pair, circle the chemical species that you would expect to be the most soluble in water.
Which of the following compounds is most soluble in water? 
Predict which of the following substances would be more soluble in water than in heptane. a. Table salt, NaCIb. Octane, C8H18c. Ethanol, CH3CH2OHd. Chlorine, Cl2e. Benzene, C6H6 
Which molecule is most soluble in waterCH3(CH2)4NH2C3H8CH3CH2CH2CH2OHCH3OH
Would you expect ethylamine to dissolve in water? H2C=CH2-NH2 (a) Yes (b) No
Which one of the following two compounds is expected to be more soluble in benzene (C6H6)? Compound I is more soluble in benzene. Compound II is more soluble in benzene.
Rank these compounds by their expected solubility in hexane, C6H14.
Which molecule is most soluble in water? (i) CH3(CH2)4NH2 (ii) C3H8 (iii) CH3CH2CH2CH2OH (iv) CH3OH
Which compound is the most soluble in water? (i) CH3CH2CH3(ii) CH3CH2CH2CH3 (iii) CH3CH2CH2CH2OH (iv) CH3CH2CH2OH (v) CH3CH2CH2CH2CH2CH2CH2CH3
Which of the following molecules would be the least soluble in water? A. CH3CH2CHO B. CH3CH2CH2OH C. CH3CH2-O-CH3 E. CH3CH2CH2CH3