organic Flashcards
what is the general formula
an algebraic formula that can be used to describe any member in a family of compounds
what is the homologous series
a group of compounds with the same functional group and general formula
what are the properties of structural isomers
they have the same molecular formula but different structural formula
what is a molecular formula
actual number of atoms of each element in a molecule
why do atoms in an alkane form tetrahedral shapes
because it has 4 bonds around each atom so bond angle around each atom is 109 as they all repel the same amount
how do sigma bonds form in alkanes
2 outer atomic orbitals overlap and combine to form a shared orbital that bonds the two atoms together , the more they overlap the stronger the bond
can atoms rotate around a sigma bond
yes
what makes a sigma bond strong
High electron density between the two nuclei means strong electrostatic attractions between molecules
what causes the low reactivity of alkanes
High bond enthalpy and low polarity of the c-c and c-h bonds so they don’t attract charged particles to react with
why do longer chain alkanes have higher boiling points than short chain or branched alkanes
because the longer chain alkanes have a higher molecular surface area and more electrons interacting meaning that there are more London forces
why is carbon monoxide lethal
it is better at binding to the haemoglobin in blood than oxygen is
what is heterolytic fission
when bond breaks evenly and 1 bonded atom receives both electrons from bonded pair forming a cation and an anion
what is homolytic fission
bond breaks evenly and each bonded atom receives 1 electron from the bonding pair forming 2 radicals
what is a radical
a species with an unpaired electron
what happens during initiation
radicals produced usually through photodissociation
what happens during propogation
radicals are created and used up in a chain reaction
what happens during termination
radicals are mopped up , the 2 join together and make a stable molecule to terminate the chain reaction
why can a mixture of products be created in a free radical reaction
because the reaction can keep going to form other compounds until it is terminated and also can take place at any point on the carbon chain so a mix of isomers may be formed
what is the structure of the double bond in alkenes
one sigma bond and one pi bond
how is a pi bond formed
when two p orbitals overlap sideways
why are pi bonds weaker than sigma bonds
because the electron density is spread out above and below the nuclei so the electrostatic attraction between the nuclei and shared electrons is weaker giving them a low bond enthalpy
why are alkenes so reactive
due to the low bond enthalpy of the pi bond , And bond sticking out causing attack from electrophiles
why do alkenes form a trigonal planar shape
because the 3 bonds repel each other
what are the structures of stereoisomers
molecules that have the same structural formula but different arrangements of the atoms in space
what is an electrophile
an electron pair acceptor
