# How do you represent "2-methyl, 3-ethylnonane"?

Mar 15, 2017

#### Explanation:

Structural formula:(Hydrogen is attached to complete Every carbon's valency {but I've not shown here as it is understood, so don't get confused)

$\textcolor{w h i t e}{a . a a a a a a a a a a a} {\text{CH"_2-"CH}}_{3}$
$\textcolor{w h i t e}{a a a a a a a a a a a a a} |$
$\textcolor{w h i t e}{a a . a a} \text{C"-"C"-"C"-"C"-"C"-"C"-"C"-"C"-"C}$
$\textcolor{w h i t e}{a a a a a a a a a} |$
$\textcolor{w h i t e}{a a a a a a a a .} {\text{CH}}_{3}$

Condensed Structural formula:

${\text{CH"_3-"CH"("CH"_3)-"CH"("CH"_2-"CH"_3)-"CH"_2-"CH"_2-"CH"_2-"CH"_2-"CH"_2-"CH}}_{3}$

Mar 15, 2017

${C}_{12} {H}_{26}$

#### Explanation:

Draw the alkane parent, the nonane:

${\text{H"_3"CCH"_2"CH"_2"CH"_2"CH"_2"CH"_2"CH"_2"CH"_2"CH}}_{3}$

Single out the carbons on the chain that require substitution: ${\text{C}}_{2}$ and ${\text{C}}_{3}$:

${\text{H"_3"C"color(red)("C")"H"_2color(red)("C")"H"_2"CH"_2"CH"_2"CH"_2"CH"_2"CH"_2"CH}}_{3}$

Substitute these positions with $\text{methyl}$ and $\text{ethyl}$ groups:

${\text{H"_3"C"color(red)("C")"H"("CH"_3)color(red)("C")"H"("CH"_2"CH"_3)"CH"_2"CH"_2"CH"_2"CH"_2"CH"_2"CH}}_{3}$

Of course, you could condense this a bit; it is important to get the condensed formula right, i.e. ${\text{C"_12"H}}_{26}$, i.e. this follows the general formula, ${C}_{n} {H}_{\text{2n+2}}$, a saturated alkane as required.