Chapter 3 Flashcards
Four emergent properties of water
Cohesion, temperature moderation, expansion upon freezing and the solvent of life
Cohesion
The attraction between water molecules due to hydrogen bonding
Adhesion
The clinging of one substance to another
Surface tension
A measure of how difficult it is to break the surface of a liquid
Kinetic energy
The energy of motion
Thermal energy
The energy in a system due to its temperature. The kinetic energy associated with the random movement of atoms or molecules
Temperature
A measure of energy that represents the average kinetic energy of the molecules in a body of matter
Heat
Thermal energy in transfer from one body of matter to another
Calorie (cal)
The amount of heat it takes to raise the temperature of 1 g of water by 1°C.
1 cal = 4.184 J (joules)
Specific heat
The amount of heat that must be absorbed or lost for 1 g of a substance to change its temperature by 1°C
Heat of vaporization
The quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state
Evaporative cooling
As a liquid evaporates, the surface of the liquid that remains behind cools down (its temperature decreases)
Solution
A liquid that is a completely homogeneous mixture of two or more substances
Solvent
The dissolving agent of a solution
Solute
The substance that is dissolved in a solution
Aqueous solution
A solution in which the solute is dissolved in water
Hydration shell
The sphere of water molecules around each dissolved ion
Hydrophilic
Any substance that has an affinity for water
Hydrophobic
A substance that is repelled by water
Molecular mass
The sum of the masses of all the atoms in a molecule
Mole (mol)
An exact number of objects: 6.02 * 10^23 (Avogadro’s number). There are exactly so many daltons in one gram.
Molarity
The number of moles of solute per liter of solution
Acid
a substance that increases the hydrogen ion concentration of a solution (hydrochloric acid)
Base
A substance that reduces the hydrogen ion concentration of a solution (sodium hydroxide)
Acid rain
Rain that is acidic (pH below 5.2)
Ocean acidification
When CO2 dissolves in seawater, it reacts with water to
form carbonic acid, which lowers ocean pH
