Organic Chemistry Chapter 1: Alkanes and Chemical Bonds

What is the characteristic of alkanes in terms of polarity?

What is the approximate density range of alkanes?

What is the state of alkanes with 1-4 carbon atoms at room temperature?

What is the purpose of applying paraffin wax to fruits and vegetables?

What is the common name for a hydrocarbon mixture with 25 or more carbon atoms?

What is the characteristic of alkanes with 9-17 carbon atoms?

What type of bond results from the transfer of electrons?

What is the typical bond of compounds of carbon?

What happens when the atomic orbitals of two carbon atoms overlap?

What is the hybridization of carbon when it is bound to two other atoms with the help of two double bonds or one single and one triple bond?

What is the bond angle in a molecule with sp hybridization?

What is the hybridization of a carbon atom when it bonds with three other atoms?

What is the arrangement of bonds in a molecule with sp3 hybridization?

What is the number of hybrid orbitals formed when carbon atoms bond to 4 other atoms?

Chemical Bonds

Ionic bonds result from the transfer of electrons
Covalent bonds result from the sharing of electrons
Covalent bonds are typical of carbon compounds and are of chief importance in organic chemistry

Hybrid Orbitals

Hybrid orbitals are formed by mixing (hybridizing) carbon's atomic orbitals
When carbon bonds to 4 other atoms, the 2s orbital and all three 2p orbitals in the valence shell combine to produce four sp3 hybrid orbitals
Hybrid orbitals are used to describe the bonds between carbon atoms

sp Hybridization

Carbon has sp hybridization when bound to two other atoms with the help of two double bonds or one single and one triple bond
sp hybridization results in a linear arrangement of atoms with a bond angle of 180°

sp2 Hybridization

Carbon is sp2 hybridized when bonding takes place between 1 s-orbital with two p orbitals
sp2 hybridization results in a triangular arrangement of atoms with 120° angles between bonds

sp3 Hybridization

Carbon has sp3 hybridization when bonded to four other atoms
sp3 hybridization results in a tetrahedral arrangement of atoms with a bond angle of 109.5°
Example: Hybridization of CH4 (Methane)

Properties of Alkanes

Alkanes are nonpolar, making them insoluble in water but soluble in nonpolar solvents
Alkanes have densities from 0.62 g/mL to about 0.79 g/mL, which is less than the density of water (1.0 g/mL)
Alkanes with 1-4 carbon atoms are gases at room temperature and are widely used as heating fuels
Alkanes with 5-9 carbon atoms are liquids at room temperature and are used in fuels such as gasoline
Alkanes with 9-17 carbon atoms have higher boiling points and are found in kerosene, diesel, and jet fuels
Alkanes with 18 and more carbon atoms are waxy solids at room temperature and are used in waxy coatings
Alkanes with 25 and more carbon atoms are semi-solid mixtures of hydrocarbons used in ointments, cosmetics, and as a lubricant (e.g. Vaseline)

Lecture 1 of Organic Chemistry course at Al Turath University covering alkanes and chemical bonds, including ionic and covalent bonds. Perfect for pharmacy students.