Question

Question: Draw all possible isomers for each molecular formula.

a. ${\mathbf{C}}_{\mathbf{3}}{\mathbf{H}}_{\mathbf{7}}\mathbf{Cl}$(two isomers)

b. ${\mathbf{C}}_{\mathbf{2}}{\mathbf{H}}_{\mathbf{4}}\mathbf{O}$ (three isomers)

c. ${\mathbf{C}}_{\mathbf{3}}{\mathbf{H}}_{\mathbf{9}}\mathbf{N}$ (four isomers)

Short answer

Answer

The different isomers for each molecular formula are given below:

a.

b.

c.

Step-by-step solution

Step-by-Step SolutionStep 1: Isomers

Isomers are compounds comprising identical chemical formulas but have various chemical structures. The phenomenon of isomerism is shown by compounds that are referred to as isomers.

Isomers of  C3H7Cl

a. The unsaturation number or double bond equivalence for this molecular formula can be calculated as follows:

$\begin{array}{rcl}\mathrm{D}.\mathrm{B}.\mathrm{E}& =& \frac{1}{2}\left[\left(2\times \mathrm{number}\mathrm{of}\mathrm{carbon}\right)+2-\left(\mathrm{numbe}\mathrm{of}\mathrm{carbon}+\mathrm{halogen}\right)\right]\\ & =& \frac{1}{2}\left[\left(2\times 3\right)+2-\left(7+1\right)\right]\\ & =& \frac{1}{2}\left[8-8\right]\\ & =& 0\end{array}$

This means that the isomers possible for this following molecule will be chloroalkane.

The possible isomers of ${\mathrm{C}}_3{\mathrm{H}}_7\mathrm{Cl}$are given below:

Representation of isomers of${\mathrm{C}}_3{\mathrm{H}}_7\mathrm{Cl}$

Molecule (1) is 1-chloropropane, and molecule (2) is 2-chloropropane.

 Step 3: Isomers of C2H4O

b. The double bond equivalence for${\mathrm{C}}_2{\mathrm{H}}_4\mathrm{O}$is given below:

$\begin{array}{rcl}\mathrm{D}.\mathrm{B}.\mathrm{E}& =& \frac{1}{2}\left[\left(2\times 2\right)+2-4\right]\\ & =& 1\end{array}$

This means that the possible compounds for ${\mathrm{C}}_2{\mathrm{H}}_4\mathrm{O}$ can contain a cyclic ring or one double bond. So, it can be a cyclic ether or an aldehyde, or an enol.

The different isomers of ${\mathrm{C}}_2{\mathrm{H}}_4\mathrm{O}$ are given below:

Representation of several isomers of ${\mathrm{C}}_2{\mathrm{H}}_4\mathrm{O}$

Molecule (1) is vinyl alcohol (tautomer of ethanal), molecule (2) is ethanol, and molecule 3 is oxirane.

Isomers of C3H9N

c. The double bond equivalence for${\mathrm{C}}_3{\mathrm{H}}_9\mathrm{N}$can be given as follows:

$\begin{array}{rcl}\mathrm{D}.\mathrm{B}.\mathrm{E}& =& \frac{1}{2}\left[\left(2\times 3\right)+2+1-9\right]\\ & =& 0\end{array}$

Thus, all the compounds must be alkanamine.

The different isomers of ${\mathrm{C}}_3{\mathrm{H}}_9\mathrm{N}$are given below:

Representation of several isomers of ${\mathrm{C}}_3{\mathrm{H}}_9\mathrm{N}$