Chapter 3: Water and Life

water is a…

polar molecule

the oxygen in a water molecule is more electronegative

true

cohesion

a phenomena where hydrogen bonds hold water molecules together

surface tension

a measure of how difficult it is to stretch or break the surface of a liquid

can water absorb/store a high or low amount of heat?

high

kinetic energy

energy of motion

temperature

average kinetic energy of the molecules in a body of matter

thermal energy

kinetic energy associated with random motion of atoms or molecules

calorie (cal)

amount of heat required to raise the temperature of 1 g of water by 1ºC

specific heat

the amount of heat that must be absorbed or lost for 1 g of that
substance to change its temperature by 1ºC

specific heat of water is

high

hydrogen bonds ___ when heat is absorbed

break

hydrogen bonds ___ when heat is released

form

heat of vaporization

heat a liquid must absorb for 1 g to be converted to gas

solvent

dissolving agent of a solution

solute

substance that is dissolved

aqueous solution

one in which water is the solvent

solution

liquid that is a completely homogeneous mixture of substances

molarity

the number of moles of solute per liter of solution

molecular mass

sum of all masses of all atoms in a molecule

1 mole (mol) =

6.02 × 10^23 molecules

buffer

substance that minimize changes in concentrations of H+ and OH– in a solution

acidic solution

ph <7

basic solution

ph >7

acid

substance that increases the H+ concentration of a solution

base

substance that reduces the H+ concentration of a solution

examples of hydrophobic molecules

fats, lipids, waxes

long chains of carbon and hydrogen bonds are…

hydrophobic

ocean acidification

process where carbon dioxide dissolves in seawater forming carbonic acid