[11.1 & 11.3] basic concepts + representing formulae

Question 1

what is catenation and how does it relate to carbon?

Answer 1

• catenation is the ability to form bonds between atoms of the same element
• carbon forms chains and rings, with single, double, and triple covalent bonds, because it is able to form strong covalent bonds with other carbon atoms

Question 2

what is a homologous series?

Answer 2

a family of compounds with similar chemical properties whose successive members differ by the addition of a -CH₂ - group

Question 3

what is a functional group?

Answer 3

• it is the part of the organic molecule that is largely responsible for the molecule’s chemical properties
• it determines the chemistry of organic compounds

Question 4

what is the molecular formula?

Answer 4

the exact number of atoms of each element present in the molecule

Question 5

what is the empirical formula?

Answer 5

the simplest whole number ratio of atoms in the molecule

Question 6

what is the structural formula?

Answer 6

the minimal detail using conventional groups, for an unambiguous structure (eg. CH₃CH₂CH₂CH₃)

Question 7

what is the displayed formula?

Answer 7

it shows both the relative placing of atoms and the number of bonds between them. all bonds are shown and double as =

Question 8

what is the skeletal formula?

Answer 8

it is used to show a simplified organic formula by removing hydrogen atoms from alkyl chains, leaving just a carbon skeleton and associated functional groups

Question 9

what is the general formula?

Answer 9

it represents any member of a homologous series (eg. for alkanes it is CₙH₂ₙ₊₂)

• the formula does not apply for cyclic compounds