1.1 Why is the boiling point of water higher than that of other solvents? What about its melting
point and its heat of evaporation?
- Intramolecular cohesion due to hydrogen bonding causes a strong lattice to be
- Boiling point is higher because it is hard to break the H bonds.
- Meltin point is high
- Heat of vaporization is also high
1.2 Is the attraction between Na+ and Cl- higher in water or in methanol?
The attraction of Na and Cl is higher in methanol because water forms stronger hydration
pockets around the ions in the solution preventing the ions from re-combining.
2 But in the most important reaction of life, the burning of carbon bonds to produce energy is
water a substrate or is it a product? How do you reconcile this with the above?
Burning Carbon bonds involves oxygen as an agent that breaks down the bonds producing
water and CO2. Therefore, water is a product. This is not either catabolic or anabolic.
3.1 Give three very general hydrophilic groups:
- Polar groups
- Groups with a positive charge
- Groups with a negative charge
3.2 What compartment does oxygen prefer? Salt? Benzene?
Since oxygen is a diatomic molecule it is nonpolar. Salt is a polar molecule because it is
charged, while benzene is nonpolar. Therefore, oxygen would prefer benzene.
3.3 How will you tell if a molecule is hydrophobic or hydrophilic?
A polar molecule is hydrophilic, while a hydrophobic molecule is nonpolar.