Question

Write the formula of (a) dipropyl ether; (b) dipentyl ether; (c) ethyl propyl ether.

Short answer

The formulas are (a) C3H7-O-C3H7 for dipropyl ether, (b) C5H11-O-C5H11 for dipentyl ether, and (c) C2H5-O-C3H7 for ethyl propyl ether.

Step-by-step solution

- Understanding Ether Nomenclature

The general formula for an ether is R-O-R', where R and R' are alkyl or aryl groups. To name ethers systematically, the alkyl or aryl groups attached to the oxygen are named in alphabetical order, followed by the word 'ether'.

- Writing the Formula for Dipropyl Ether

Dipropyl ether has two identical propyl groups attached to the oxygen atom. The propyl group has a three-carbon chain, so the formula for one propyl group is C3H7. Since we have two propyl groups in dipropyl ether, the formula becomes C3H7-O-C3H7.

- Writing the Formula for Dipentyl Ether

Dipentyl ether has two identical pentyl groups attached to the oxygen atom. The pentyl group has a five-carbon chain, therefore the formula for one pentyl group is C5H11. Hence, the formula for dipentyl ether is C5H11-O-C5H11.

- Writing the Formula for Ethyl Propyl Ether

Ethyl propyl ether has an ethyl group and a propyl group attached to the oxygen atom. The ethyl group has a formula of C2H5 and the propyl group has a formula of C3H7. Therefore, the formula for ethyl propyl ether is C2H5-O-C3H7.

Key concepts

Understanding Organic Chemistry

Organic chemistry is a subdiscipline of chemistry that deals with the structure, properties, and reactions of organic compounds and materials. In essence, it is the study of carbon-containing compounds, which includes a wide range of molecules, from simple hydrocarbons to complex polymers and biological macromolecules.

The versatility of carbon allows it to form strong bonds with other carbon atoms as well as with elements such as hydrogen, oxygen, nitrogen, and halogens, which leads to an immense variety of possible compounds. In the case of ethers such as dipropyl ether or dipentyl ether, understanding organic chemistry principles enables us to identify the molecule's structure, the types of bonds present, and the corresponding chemical behavior.

Identifying Functional Groups

Functional groups are specific groupings of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. They are the reactive parts of molecules and often determine the molecule's overall properties.

In organic chemistry, the ether functional group is characterized by an oxygen atom connected to two alkyl or aryl groups. This group is easily identifiable due to its R-O-R' general structure. Its presence in a compound like ethyl propyl ether largely defines how the compound will react with other substances. For instance, ethers generally have low reactivity, but they are excellent solvents for a wide range of chemical reactions.

Recognizing Alkyl Groups

Alkyl groups are types of hydrocarbon chains that are important building blocks in the structure of organic molecules, forming part of larger structures. They are essentially parts of molecules that would be alkanes if they were not attached to something else — think of them as trees with one of their branches removed.

Some common examples include ethyl (C2H5) and propyl (C3H7) groups. These alkyl groups are named based on the number of carbon atoms they contain and their structure, whether they are straight-chained or branched. In the exercises for dipropyl and dipentyl ethers as well as ethyl propyl ether, correctly identifying these groups helps us to write the molecular formula accurately. Alkyl groups are not only essential in nomenclature but also influence the physical and chemical properties of the molecule.