introduction to organic chemistry

Question 1

what can carbon form

Answer 1

carbon can form rings and very long chains, which can be branched

Question 2

why can carbon form rings ad very long branches

Answer 2

a carbon atom has four electrons in its outer shell, so it forms four covalent bonds

carbon-carbon bonds are relatively string (347 KJ MOL^-1) and non-polar

Question 3

what other carbon bond is strong

Answer 3

the carbon-hydrogen bond is also strong (413 KJ mol^-1) and relatively non-polar.

hydrocarbon chains form the skeleton of most organic compounds

Question 4

what were organic compounds originally thought to be

Answer 4

organic compounds were originally thought to be produced by living things only. this was disapproved by Friedrich Wohler in 1828.

Question 5

what happens in all stable carbon compounds

Answer 5

in all stable carbon compounds, carbon forms four covalent bonds and has eight electrons in its outer shell

Question 6

what are the different ways carbon forms bonds

Answer 6

by forming four single bonds as an alkane

by forming two single bonds and one double bond as an alkene

by forming one single bond and one triple bond as an alkyne

Question 7

what are the different types of formula

Answer 7

General formula

Empirical formula

Molecular formula

structural formula

skeletal formula

displayed formula

Question 8

define general formula

Answer 8

an algebraic formula that can describe any member of compounds

Question 9

define the empirical formula

Answer 9

the simplest ratio of atoms of each element in a compound

Question 10

define molecular formula

Answer 10

the actual number of atoms of each element in a molecule

Question 11

define structural formula

Answer 11

shows the bonds of the carbon skeleton only, with any functional groups

the hydrogen and carbon atoms arent shown

this is handy for drawing large complicated structures, like cyclic hydrocarbons

Question 12

define displayed formula

Answer 12

shows how all the atoms are arranged and all the bonds between them

Question 13

define the homologous series

Answer 13

a homologous series is a group of compounds that contain the same functional group.

they can all be represented by the same general formula

Question 14

what can you use the general formula for

Answer 14

you can use the general formula to work out the molecular formula of any member of a homologous series

each successive number of a homologous series differes by a CH2 group

Question 15

what are the main homologous series

Answer 15

alkanes

branched alkanes

alkenes

halogenalkanes

alcohols

aldehydes

ketones

carboxylic acids

esters

amines

amides

acyl chlorides

cycloalkanes

arenes

Question 16

since electrons are negatively charged what do they do during reactions

Answer 16

as electrons are negatively charged they tend to move from areas of high electron density to more positively charged areas.

Question 17

how is the movement of electrons shown in a formula

Answer 17

The movement of a pair of electrons is shown by a curly arrow that starts from a lone pair of electrons or from a covalent bond and moves towards the positively charged area of a molecule to form a new bond

Question 18

explain what a free radical is and how they occur

Answer 18

sometimes a covalent bond may break in such a way that one electron goes to each atom that originally formed the bond

these fragments of the original molecule have an unpaired electron and are called free radicals

they are usually extremely reactive

Question 19

what does IUPAC stand for

Answer 19

international union of pure and applied chemistry