Question

1. Explain the shape of the water molecule. How is its unequal charge distributed over that shape? Briefly mention how this ‘unequality’ affects properties of water.

2. Describe in detail how the hydrogen bonds contribute to the high boiling and melting point? How is it related to specific heat?

3. Describe the ionization of water. How does Kw relate to the pH scale?

Answer 1

1)

2. Water in its liquid form has an unusually high boiling point temperature, a value close to 100°C. As a result of the network of hydrogen bonding present between water molecules, a high input of energy is required to transform one gram of liquid water into water vapor, an energy requirement called the heat of vaporization. Water has a heat of vaporization value of 40.65 kJ/mol. A considerable amount of heat energy (586 calories) is required to accomplish this change in water.

3.H₂O H⁺ + OH^-
K_w = [H⁺][OH^-]

pK_w = -log₁₀(K_w )