Module 4 Flashcards
What is the general formula for an alkane?
CnH2n+2
What is the general formula for an alkene?
CnH2n
What is the general formula for an alcohol?
CnH2n+1OH
What is meant by the term structural isomer?
Compounds with the same molecular formula but different structural formulae.
What is meant by the term stereoisomers?
Organic compounds with the same molecular and structural formulae but having a different arrangement of atoms in space.
What is meant by the term homolytic fission?
When a covalent bond breaks and each bonding atom receives one electron from the bonded pair, forming two radicals.
What is meant by the term heterolytic fission?
When a covalent bond breaks and one bonding atom receives both electrons from the bonding pair.
What is meant by the term radical?
A highly reactive species with one or more unpaired electrons.
What is meant by the term curly arrow?
Model the flow of electron pairs during reaction mechanisms.
What is meant by the term electrophile?
An electron-pair acceptor.
What is meant by the term nucleophile?
An electron-pair donor.
What is the shape and bond angle around a C in an alkane?
Tetrahedral, 109.5
Which factors affect boiling points of alkanes? How?
- carbon chain length, increases as length increases, more London forces
- branching, decreases as branching increases, fewer London forces
Why do alkanes have a low reactivity?
High bond enthalpies, low polarity
What are the potential dangers of CO?
- toxic gas, odourless and colourless
- diffuses into blood and forms coordinate bonds to Fe in haemoglobin instead of oxygen
- organs become oxygen deprived
What are the conditions required for the halogenation of an alkane?
UV light
What are the three stages of free radical substitution?
Initiation, propagation and termination
What are the limitations of radical substitution?
- can further substitute
- difficult to control
- mixture of products forms
What is the shape and bond angle around a C in an alkene functional group?
Trigonal planar, 120
How does the pi-bond form?
Sideways overlap of adjacent p-orbitals above and below the bonding C atoms.
What is required for a molecule to have stereoisomerism?
- restricted rotation around the C=C
- 2 different groups attached to each C in the C=C
Why are alkenes more reactive than alkanes?
- lower bond enthalpy of the pi-bond
- C=C has high electron density to attract electrophiles
What are the conditions for the hydrogenation of an alkene?
150 degrees
Ni catalyst
What are the conditions for the hydration of an alkene?
- phosphoric acid
- 300 degrees, 65 atm.
