Chapter 15: Alcohols

Question 1

What is the general formula for an alcohol?

Answer 1

CnH2n+1OH

Question 2

what is the alcohol with 5 carbons called?

Answer 2

pentanol

Question 3

What are the two methods of ethanol production?

Answer 3

1 Making ethanol from crude oil by cracking and hydration of alkenes
in the presence of an acid catalyst
2 Making ethanol by fermentation

Question 4

What are the conditions needed for the production of ethanol by fermentation and why?

Answer 4

1 Temperature = 35*c  (any higher causes enzymes o denature and become ineffective)
2 Vacuum (air is kept out to prevent the oxidation of ethanol to ethanoic acid)
3 Alcohol concentration  less than 15% (any higher prevents enzymes from being able to function)

Question 5

What are the three classification groups for alcohols?

Answer 5

1 Primary alcohols
2 Secondary alcohols
3 Tertiary alcohols

Question 6

What is the definition of a primary alcohol?

Answer 6

A carbon with the -OH group at the end of a chain, one R-group and two hydrogen atoms

Question 7

What is the definition of a secondary alcohol?

Answer 7

A carbon with the -OH group in the body of the chain, two R-groups and one hydrogen atom

Question 8

What is the strongest intermolecular bonding that occurs between alcohol molecules and why?

Answer 8

Hydrogen bonding - due to the dipole -OH group

Question 9

Why do alcohols have higher melting and boiling points than alkanes?

Answer 9

Alcohols form hydrogen bonds which is a stronger intermolecular force than the van der waals forces produced by alkanes

Question 10

Are short chain or long chain alcohols more soluble and why?

Answer 10

Short chain - they have a shorter non polar hydrocarbon chain so a greater proportion of the molecule is soluble