Skip to main content
Ch. 2 - Acids and Bases; Functional Groups
Wade - Organic Chemistry 9th Edition
Wade9th EditionOrganic ChemistryISBN: 9780135213728Not the one you use?Change textbook
Chapter 2, Problem 7a

Circle the member of each pair that is more soluble in water.
a. CH3CH2OCH2CH3 or CH3CH2CH2CH2CH3
b. CH3CH2OCH2CH3 or CH3CH2CH2OH
c. CH3CH2NHCH3 or CH3CH2CH2CH3
d. CH3CH2OH or CH3CH2CH2CH2OH
e.

Verified step by step guidance
1
Identify the functional groups in each compound. For example, ethers (R-O-R') and alcohols (R-OH) are more polar than alkanes (R-R') and can form hydrogen bonds with water, increasing solubility.
For part (a), compare CH3CH2OCH2CH3 (an ether) with CH3CH2CH2CH2CH3 (an alkane). Ethers are generally more soluble in water than alkanes due to their ability to form hydrogen bonds.
For part (b), compare CH3CH2OCH2CH3 (an ether) with CH3CH2CH2OH (an alcohol). Alcohols can form more hydrogen bonds with water than ethers, making them more soluble.
For part (c), compare CH3CH2NHCH3 (an amine) with CH3CH2CH2CH3 (an alkane). Amines can form hydrogen bonds with water, increasing their solubility compared to alkanes.
For part (d), compare CH3CH2OH (a primary alcohol) with CH3CH2CH2CH2OH (a primary alcohol with a longer carbon chain). Shorter chain alcohols are generally more soluble in water than longer chain alcohols due to less hydrophobic character.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
5m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Polarity and Solubility

Polarity refers to the distribution of electrical charge over the atoms in a molecule. Polar molecules, which have a significant difference in electronegativity between atoms, tend to dissolve well in polar solvents like water. Understanding the polarity of the compounds in the question is crucial for predicting their solubility in water.
Recommended video:
Guided course
07:13
Functional Classification

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In the context of solubility, groups such as hydroxyl (-OH) and amino (-NH2) are polar and can form hydrogen bonds with water, enhancing solubility. Identifying these groups in the given compounds is essential for determining which is more soluble.
Recommended video:
Guided course
02:36
Identifying Functional Groups

Hydrogen Bonding

Hydrogen bonding is a type of attractive interaction between a hydrogen atom bonded to a highly electronegative atom and another electronegative atom. This interaction significantly influences the solubility of compounds in water. Molecules capable of forming hydrogen bonds with water will generally be more soluble, making it important to assess the ability of the compounds in the question to engage in such interactions.
Recommended video:
Guided course
00:48
The definition of hydrogenation.