CHEM - 11. intro to organic

Emprirical formula

The simplest ratio of each type of atom in an organic compound e.g. Ethane is CH₃

Molecular formula

Provides the number of each different type of atom in an organic compound e.g. Ethane is C₂H₆

Structural Formula

shows how the atoms in an organic compound are bonded to one another, it is a shorthand notation that takes each carbon atom in an organic compound in turn and explains what is attached to it. e.g. Ethane is CH₃CH₃

Displayed formula

A diagram the shows all the bonds in an organic compound using lines e.g. ETHANE

General formula

Relates the number of each type of atom in an organic compound to the number of carbons in a chain e.g. alkanes is C_nH_2n+2

Hydrocarbon

A compound containing only carbon and hydrogen atoms

Homologous series

Is a group of compounds which contain the same functional group and have the same general formula, members of homologous series differ from one another by CH₂, Have similar chemical properties and have trends in their physical properties

Functional group

Is the group of atoms that give an organic compound its chemical properties e.g. -OH in alcohols, or C=C in alkenes

Isomer

Have the molecular formula but a different structural formula, that means there are the same number of atoms of each type present but they are bonded in a different order

saturated

Contains no C=C double bonds

substiution

a reaction in which one group of atoms ( or atom ) is swapped with another

combustion

A reaction that involves burning in a source of oxygen i.e in air

What are the Alkanes in order

Methane

Ethane

Propane

Butane

Pentane

Hexane

How many C atoms does Propane have

3

Molecular formula of Pentane

C₅H₁₂

displayed formula of Butane

H H H H

H - C - C - C - C - H

H H H H

What is substitution

A reaction in which one group of atoms is swapped with another

products of combustion

CO₂ + H₂O

Method of fractional distillation

• crude oil is evaporated and heated

• fractioning column is hotter at the bottom and cooler at the top

• different fractions have different boiling points

• different fractions cool and condense at different levels

fractions of crude oil from lightest to heaviest and their uses

• refinery gases - gas ovens and heating

• gasoline/ petrol - vehicles

• kerosene - airplanes

• diesel - vehicles

• fuel oil - ships, factories

• bitumen - roads and roofing

How do you make crude oil useful

separate it into fractions

different fractions of crude oil…

have different boiling point ranges

What is cracking

when long chain alkanes are broken down into more useful products, e.g. short chain alkanes are in higher demand

what does cracking require

heat and catalyst

describe carbon monoxide

It is a toxic substance made from incomplete combustion

it is colourless, tasteless and odourless and therefore difficult to detect

talk about impurities in fuels, hydrocarbons

hydrocarbons fuels contain Sulfur impurities, this produces Sulphur dioxide when burned in air which causes acid rain

what are properties of fractions at the bottom

• darker, thicker, higher melting point and larger molecules

• cheaper - less demand

What is crude oil

a mixture made of many different hydrocarbon chains of different lengths

structural formula of Pentane

CH₃CH₂CH₂CH₂CH₃

what is the key condition of substitution reactions of alkanes with halogens

UV light

Isomer of butane name

2- methyl propane

Isomers of pentane

3/2 - Methyl Butane

2,2 - dimethyl propane

describe the test for water

anhydrous copper sulphate

white to blue if positive

What colour does bromine change in an alkene

orange-brown to colourless