Question

Use the octet rule to draw Lewis dot structures for all the stable molecules with the molecular formula \(\mathrm{C}_{3} \mathrm{H}_{8} \mathrm{O}\) . There are thre total molecules.)

Short answer

The three stable molecules are Propanol, Isopropanol, and an Ether (CH3CH2OCH3).

Step-by-step solution

Define the Octet Rule

The octet rule states that atoms tend to form molecules where they have eight electrons in their valence shell, achieving a noble gas electron configuration. In drawing Lewis structures, the aim is to position electrons so that each atom (except hydrogen, which follows the duet rule) has eight electrons around it.

Count Valence Electrons

Count the total number of valence electrons available for the molecular formula \(\mathrm{C}_{3} \mathrm{H}_{8} \mathrm{O}\). Carbon (\(\mathrm{C}\)) has 4 valence electrons, hydrogen (\(\mathrm{H}\)) has 1 valence electron, and oxygen (\(\mathrm{O}\)) has 6 valence electrons. Thus, for \(\mathrm{C}_3\mathrm{H}_8\mathrm{O}\):\[(3 \times 4) + (8 \times 1) + 6 = 26\text{ valence electrons}\]

Draw the First Molecule Structure (Propanol)

Draw the structure with carbons in a chain, an oxygen bonded to the terminal carbon, and place hydrogen atoms to complete the structure. Ensure each atom satisfies the octet rule, except hydrogen, which should have two electrons. The structure is CH3-CH2-CH2-OH.

Draw the Second Molecule Structure (Isopropanol)

Draw the structure with two carbons bonded to each other and the third carbon bonded to them, creating a branching point. Attach the oxygen to the central carbon and complete with hydrogen atoms. The structure is (CH3)2CHOH, ensuring all elements satisfy their required electron configurations.

Draw the Third Molecule Structure (Ethers)

Construct a structure where the oxygen atom is between two carbon atoms, thus forming an ether. Add the remaining hydrogen atoms to satisfy valence requirements on all carbons. A possible structure is CH3CH2OCH3, ensuring all carbons and oxygens follow the octet rule.

Key concepts

Octet Rule

The octet rule is a fundamental concept in chemistry that describes how atoms form stable molecules by having eight electrons in their outer shell. This rule reflects the tendency of atoms to attain the electron configuration of the noble gases, known for their stability. Typically, atoms achieve this configuration by sharing, gaining, or losing electrons when forming bonds with other atoms. In the context of Lewis dot structures, the octet rule helps us determine the arrangement of electrons. However, hydrogen stands apart by following the duet rule, requiring only two electrons to achieve a stable configuration. When drawing Lewis structures, always ensure that atoms (besides hydrogen) satisfy this octet rule for stability.

Valence Electrons

Valence electrons are the electrons present in the outermost shell of an atom, playing a crucial role in bond formation. These electrons determine how atoms will interact and combine with others. For the \(\mathrm{C}_3\mathrm{H}_8\mathrm{O}\) molecule, calculating the total number of valence electrons is the first step in drawing its Lewis structures.- Carbon (\(\mathrm{C}\)) has four valence electrons.- Hydrogen (\(\mathrm{H}\)) contributes one valence electron per atom.- Oxygen (\(\mathrm{O}\)) has six valence electrons.To find the total number of valence electrons in \(\mathrm{C}_3\mathrm{H}_8\mathrm{O}\):- Three carbons: \(3 \times 4 = 12\)- Eight hydrogens: \(8 \times 1 = 8\)- One oxygen: \(1 \times 6 = 6\)Adding these gives us \(26\) valence electrons, guiding us in correctly arranging them in the molecule's structure.

Organic Chemistry

Organic chemistry is the branch of chemistry dedicated to the study of carbon-containing compounds, known as organic compounds. These compounds form the basis of life and include a variety of structures ranging from simple molecules to complex macromolecules.- Carbon's ability to form four covalent bonds enables the vast diversity of organic compounds.- In organic chemistry, compounds like \(\mathrm{C}_3\mathrm{H}_8\mathrm{O}\) demonstrate how carbon can bond with hydrogen and oxygen to form alcohols and ethers.- This molecular flexibility is what makes organic chemistry a rich and fascinating area of study.Understanding organic chemistry involves grasping how these bonds form and break, influencing the properties and reactions of molecules. By mastering key principles, you can deepen your knowledge of how molecules interact in biological and synthetic processes.

C3H8O Molecules

The molecular formula \(\mathrm{C}_3\mathrm{H}_8\mathrm{O}\) represents several isomeric structures that illustrate the versatility of organic compounds in forming different molecules. Isomers are molecules with the same molecular formula but different arrangements of atoms.- **Propanol:** As a primary alcohol, this \(\mathrm{C}_3\mathrm{H}_8\mathrm{O}\) structure has the oxygen atom bonded to a terminal carbon, forming CH3-CH2-CH2-OH. Each carbon satisfies the octet rule, while hydrogen follows the duet rule.- **Isopropanol:** This secondary alcohol showcases branching with the formula CH3-CH(OH)-CH3, where the oxygen is bonded to the central carbon atom, also satisfying the required electron configurations.- **Ether:** The ether structure emphasizes the flexibility of \(\mathrm{C}_3\mathrm{H}_8\mathrm{O}\), displaying the formula CH3-CH2-O-CH3. Here, the oxygen is bonded between two carbons, creating variations in physical and chemical properties compared to alcohols.These structures illustrate the diversity within a single molecular formula, highlighting the creativity involved in designing and interpreting organic compounds.