1. Explain why when I was adding drops of water to a coin, the coin overflowed at eight drops of water  however, when I added a thin layer of dish soap to the coin, the coin overflowed with water after 10 drops of water. Explain this effect in terms of cohesion hydrogen bonding between like molecules, and surface tension.

2. Explain why when I added drops of water with my finger onto a clean ceramic plate, the drops of water just splashed onto the plate and made no shape. However, when I was adding drops of water with my finger onto a plate with a piece of baking paper on it, the drops of waters landed as a perfect circle with no splashes. Explain  the difference in drop shape in terms of adhesion, the formation of hydrogen bonds between molecules of different types and hydrophobic interactions. 



Place 2-3 drops of water on one of the glass slides. Lay the second slide directly over the first so the water spreads evenly. Try to pull them apart.

1a.What emergent property(ies) of water is (are) at work here? 1b.How are hydrogen bonds involved in this (these) property (properties)? 1c.Explain why glass is described as hydrophillic.

Which of the following statements about water is not true?

Water will hydrogen bond into highly ordered structures or "cages" around non-polar molecules.

The electron-rich oxygen atom of one water molecule can interact with an electron-poor hydrogen on another water molecule to form a hydrogen bond.

Water is a key player in the energetics of the hydrophobic effect.

In an ice crystal water molecules pack into open lattices consisting of five-membered oxygen rings.

At 25 degrees celsius liquid water is about 85% as hydrogen bonded as the water in ice, with each molecule in an average of 3.4 hydrogen bonds.

Which of the following is the best explanation for the hydrophobic effect?

Which of the following factors is responsible for the fact that water is a liquid at room temperature?

Select one:

a. Covalent O-H bonds

b. Ionic bonds

c. Hydrogen bonds

d. Hydrophobic bonding between water molecules

e. The molecular weight of water