chapter 12

Question 1

what are the properties of alkanes?

Answer 1

strong bonds
non-polar
reacts with oxygen in combustion to release heat

Question 1

what is a radical?

Answer 1

very reactive species with unpaired electrons formed by homolytic fission

Question 2

what are sigma bonds caused by?

Answer 2

overlap of atomic orbitals directly between bonding

Question 3

what is in the initiation step of homolytic fission?

Answer 3

Br-Br –> Br. + Br.
formation of radicals

Question 4

what is in the propagation step of homolytic fission?

Answer 4

radicals on both sides of equation e.g.
C5H12 + Br. –> C5H11 + HBr
C5H11. + Br2 –> C5H11Br + Br.

Question 5

what is in the termination step of homolytic fission?

Answer 5

two radicals colliding to form a molecule with electrons paired e.g.
Br. + Br. –> Br2

Question 6

what is heterolytic fission?

Answer 6

one of the bonded atoms takes both of the electrons from a bond (uneven split)
more electronegative one takes the electrons

Question 7

what happens to the boiling point of alkanes?

Answer 7

chain length increases
molecules have more surface area so more surface contact between molecules
so london forces are greater
need more energy to overcome them
increased boiling point

Question 8

what is structural isomerism?

Answer 8

compounds with same molecular formula but different structural formula

Question 9

what is chain isomerism?

Answer 9

carbon units in different positions

Question 10

what is position isomerism?

Answer 10

same functional group but in different position along chain

Question 11

what is functional group isomerism?

Answer 11

different functional group