Q57 E - Organic Chemistry (Mcmurry)

Question

Among the most common over-the-counter drugs you might find in a medicine cabinet are mild pain relievers such ibuprofen (Advil, Motrin), naproxen (Aleve), and acetaminophen (Tylenol). 

(a) How many sp³-hybridized carbons does each molecule have? 

(b) How many sp²-hybridized carbons does each molecule have? 

(c) Can you spot any similarities in their structures?

Step-by-Step Solution

Answer

1. Compound                $s{p}^3$ hybridized       

             Ibuprofen                        6

             Naproxen                        3

             Acetaminophen              1     

                         

    2. Compound                 $s{p}^2$  hybridized

           Ibuprofen                         7

           Naproxen                        11

           Acetaminophen               7

    3.The main similarities which we can spot is that each of the structure has a six membered ring         containing three double bonds, each has a methyl group, and each has a C=O group.

Hybridization

Hybridization is a concept of mixing atomic orbitals into new hybrid orbitals which are generally of lower energy and suitable for pairing of electrons to form chemical bonds. Hybridization of an atom can be calculated by measuring charge cloud on an atom.

Charge cloud means total number of Lone pair or bond pair on an atom. For

${\mathrm{Sp}}^3$- 4 charge clouds

${\mathrm{Sp}}^2$- 3 charge clouds

 $u$- 2 charge clouds

Calculate sp 3 hybridized carbon for each molecule

Here * represents ${\mathrm{Sp}}^3$  hybridized carbon.

 

For the molecule to have ${\mathrm{Sp}}^3$ hybridized carbon it must have four charge clouds on an atom.

In Ibuprofen we have 6 ${\mathrm{Sp}}^3$ hybridized carbon because each carbon atom has four bond pair i.e. charge cloud.

In Naproxen we have 3 ${\mathrm{Sp}}^3$ hybridized carbon because each carbon atom has four bond pair i.e. charge cloud.

In Acetaminophen we have 1 ${\mathrm{Sp}}^3$hybridized carbon because each carbon atom has four bond pair i.e. charge cloud.

Calculate sp 2 hybridized carbon for each molecule

Here # represents ${\mathrm{Sp}}^2$ hybridized carbon.

 

For the molecule to show ${\mathrm{Sp}}^2$ hybridized carbon it must have four charge clouds on an atom.

In Ibuprofen we have 7 ${\mathrm{Sp}}^2$ hybridized carbon because each carbon atom has three bond pair i.e. charge cloud.

In Naproxen we have 11  ${\mathrm{Sp}}^2$ hybridized carbon because each carbon atom has three bond pair i.e. charge cloud.

In Acetaminophen we have 7 ${\mathrm{Sp}}^2$ hybridized carbon because each carbon atom has three bond pair i.e. charge cloud.

Spotting similarities in the structure.

The main similarities which we can spot in each of the structure is;

Each of the structure has a six membered ring containing three double bonds.

Each of the structure has a methyl group.

Each of the structure has a C=O group.