The Properties of Water Are Critical to the Chemistry of Life

Question 1

Why does ice float?

Answer 1

molecules are hydrogen-bonded in a rigid, crystalline structure, the space between molecules is less dense than water

Question 2

Specific heat

Answer 2

amount of energy needed to raise temperature of 1g of a substance by 1 degree C

Question 3

Why does water have a high specific heat?

Answer 3

because of hydrogen bonding; it takes a lot of energy to break many hydrogen bonds

Question 4

Why does ice require a lot of energy to melt?

Answer 4

to break the hydrogen bonds

Question 5

Heat of vaporization

Answer 5

amount of energy needed to change one gram of a liquid substance to a gas at constant temperature

Question 6

Cohesion

Answer 6

water molecules stick to each other because of hydrogen bonds

Question 7

Adhesion

Answer 7

water molecules stick to other molecules

Question 8

Solution

Answer 8

substance (solute) dissolves in a liquid (solvent)
Ex: salt dissolves in water

Question 9

What do acids do?

Answer 9

release hydrogen ions (H+) in water

Question 10

What do bases do?

Answer 10

accept H+ ions

Question 11

pH

Answer 11

negative log of molar concentration of free H+ ions in a solution
Equation: pH = -log[H+]

Question 12

Lower pH numbers mean higher H+ concentration (greater acidity). True or False?

Answer 12

True