Flashcards in Module 4 Section 1 Deck (25)
What is the empirical formula?
The simplest whole number ratio of atoms of each element in a compound
What is the molecular formula?
Actual number of atoms of each element in a compound
What is the structural formula?
Shows the arrangement of atoms carbon by carbon with the attached hydrogen and functional groups
What is a skeletal formula?
Shows the bonds of the skeleton only, with any functional groups
What is the displayed formula?
Shows how all the atoms are arranged and the bonds between them
What is a homologous series?
Bunch of organic compounds that have the same functional group and general formula
What is the general formula for alkanes?
What is a structural isomer?
Same molecular formula but the structure is different
What are the three different types of structural formulas?
Chain isomers - carbon skeleton arranged differently - different physical properties
Positional isomers - functional group on different carbon atom - different chemical and physical properties
Functional group isomers - atoms arranged into different functional groups
Alkanes are ......
Saturated - all carbon bonds are single
What forces does an alkane have?
Covalent bonds in the molecules and induced dipole-dipole interactions holding them all together
What affects the boiling point of an alkane?
Longer= stronger - more surface area
Branches chain = lower boiling point - pack closely have smaller molecular surface area
What is produced when alkanes are burnt completely on oxygen?
Carbon dioxide and water
Why do alkanes make good fuels?
Release so much energy when the burn
All gases at the same temperature and pressure have the same ...............
What happens when alkanes are burnt in limited oxygen?
Carbon monoxide and water is produced
Why is the production of carbon monoxide a problem?
Poisonous - binds to the haemoglobin in the blood - less oxygen can be carried around the body
What is Heterolytic fission?
The bond breaks unevenly with one of the bonded atoms receiving both electrons - firms a positively charged cation and a negatively charged anion
What is homolytic fission?
The bond breaks evenly- each bonding atom receives one electron from the bonded pair - two electrically uncharged radicals are formed - very reactive
How are haloalkanes formed?
Halogens and alkanes react in photochemical reactions- started by by light - requires ultraviolet light
A hydrogen is substituted by chlorine or bromine - free-radical substitution reaction
Describe the reaction mechanism of chlorine and methane?
Institution - free radicals are produced
Sunlight provides energy to split cl2 - splits equally by homolytic fission creative a highly reactive unpaired election - few eradicate
What is a general formula?
Algebraic formula that can describe any member of a family of compounds
For free radical substitution what is the reaction mechanism
Initiation - radicals produced - bond breaks evenly in homolytic fission
Propagation - free radicals are used up and created in a chain reaction
Termination - free radicals are mopped up - stable molecule is formed when two free radicals join together
What are the problems with free radical reactions?
Mixtures are produced which need to be separated - by using excess methane there is a greater chance that cl radical will collide with methane
A mixture of positional isomers can form