Organic formulae and homologous series

What is the electronic configuration of carbon? How many electrons does it need to become stable?

1s²2s²2p² - In group 4 so has 4 electrons in its outer shell and needs 4 more electrons to become stable.

What does carbon form to become stable?

Four covalent bonds

What are the three different ways that carbon forms the four covalent bonds?

• 4 single covalent bonds

• 2 single bonds and 1 double bond

• 1 single bond and 1 triple bond

Example of carbon forming 4 covalent bonds

Methene

Example of carbon forming 2 single bonds and 1 double bond

Ethene

Example of carbon forming 1 single bond and 1 triple bond

Ethyne

Types of formula summary:

What is a molecular formula?

Gives the actual numbers of atoms of each element in a compound

What is an empirical formula?

Gives the simplest whole number ratio of atoms ofeach element in a compound

What is a displayed formula?

Shows all atoms and all bonds in a molecule

What is a structural formula?

Shows the arrangement of atoms in a formula

What is skeletal formula?

Carbon atoms are not drawn and C-H bonds aren’t drawn. The vertices represent the carbon atoms.

How would you show double bonds or elements beside carbon and hydrogen in skeletal formulae?

How would you add functional groups to skeletal formulae?

Draw a line down and add the functional group to the end in its structural formula

Skeletal formula for ethylamine - CH₃CH₂NH₂

What is homologous series?

A family of compounds with the same functional group but different chain lengths

What are functional groups?

An atom of group of atoms responsible for the characteristics/reactivity of molecules

General formula for alkanes

C_nH_2n+2

What is the functional group for alkanes?

No functional group

General formula for alkenes

C_nH_2n

What is the funtional group for alkenes?

C = C bond

What are halogenoalkanes?

Alkanes with a halogen attatched to them

General formula for halogenoalkanes

C_nH_2n+1X

What is the functional group for halogenoalkanes?

C - X

General formula for alcohols

C_nH_2n+2O

What is the functional group for alcohols?

R - OH

• R represents the carbon chain

General formula for aldehydes

C_nH_2nO

What is the functional group for aldehydes?

Homologous series of aldehydes

What is the general formula of ketones?

Same as aldehydes - C_nH_2nO

What is the functional group for ketones?

The carbonile group (C=O) is in the middle of the chain

General formula for carboxylic acids

C_nH_2nO₂

What is the functional group for carboxylic acids?

General formula for amines

C_nH_2n+2N

What is the functional group for amines?

R - NH₂

Methylamine

General formula for nitriles

C_nH_2n-1N

What is the functional group for nitriles?