Chapter 11, Problem 1E

Why do ethanol and dimethyl ether have such different properties even though they have same chemical formula?

Interpretation Introduction

To determine: Why do ethanol and dimethyl ether have such different properties even when they have same chemical formula?

Answer to Problem 1E

Solution:

The difference is caused because of different functional group present in both the compounds. Ethanol contains alcohol (-OH) functional group while dimethyl ether contains ether (-O-) group.

Explanation of Solution

The physical and chemical properties of any compound is closely related with its structure and bonding pattern.

So, to understand the difference between properties of the given compounds their structural formula are very important to be discussed.

Chemical formula of Ethanol : C₂H₆O or , C₂H₅OH

Structural formula of Ethanol :

Chemical formula of Dimethyl ether : C₂H₆O or , CH₃-O-CH₃

Structural formula of Ethanol :

The difference can be easily seen, that in one hand, where ethanol is a polar molecule with terminal −OH group having electronegativity difference and the ethanol molecules are attached together by hydrogen bonding as the H-atom is directly attached to electronegative O-atom.

While in other hand, dimethyl ether has two methyl groups attached to one other by (-O-) group on either sides which generates a regular dipole-dipole interactions.

The two types of bonding pattern bring changes in the properties of the two compounds.

Also, there are many more functional aspects of both the functional groups which change the properties of compounds instead of having same chemical formula.

Conclusion

The difference in functional groups of ethanol and dimethyl ether brings the difference in their properties.