Chapter 3

Question 1

Acid

Answer 1

A substance that increases the hydrogen ion concentration of a solution

Question 2

Adhesion

Answer 2

The clinging of one substance to another, such as water to plant cell walls by means of hydrogen bonds

Question 3

Aqueous Solution

Answer 3

A solution in which water is the solvent

Question 4

Base

Answer 4

A substance that reduces the hydrogen ion concentration of a solution

Question 5

Calorie (cal)

Answer 5

The amount of heat energy required to raise the temperature of 1 g of water by 1°C; also the amount of heat energy that 1 g of water releases when it cools by 1°C. The Calorie (with a capital C) usually used to indicate the energy content of food, is a kilocalorie

Question 6

Buffer

Answer 6

A solution that contains a weak acid and its corresponding base. A buffer minimizes changes in pH when acids or bases are added to the solution

Question 7

Cohesion

Answer 7

The linking together of like molecules, often by hydrogen bonds

Question 8

Heat of Vaporization

Answer 8

The quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state

Question 8

Evaporative Cooling

Answer 8

The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state

Question 9

Heat

Answer 9

Thermal energy in transfer from one body of matter to another

Question 10

Hydration Shell

Answer 10

The sphere of water molecules around a dissolved ion

Question 10

Hydrogen Ion

Answer 10

A single proton with a charge of 1+. The dissociation of a water molecule leads to the generation of a hydroxide ion and a hydrogen ion; in water, H+ is not found alone but associates with a water molecule to form a hydronium ion

Question 10

Hydrophilic

Answer 10

Having an affinity for water

Question 11

Hydronium Ion

Answer 11

A water molecule that has an extra proton bound to it; commonly represented as H+

Question 12

Joule (J)

Answer 12

A unit of energy

Question 12

Hydroxide Ion

Answer 12

A water molecule that has lost a proton

Question 13

Hydrophobic

Answer 13

Having no affinity for water; tending to coalesce and form droplets in water

Question 14

Kilocalorie (kcal)

Answer 14

A thousand calories; the amount of heat energy required to raise the temperature of 1kg of water by 1°C

Question 15

Molarity

Answer 15

A common measure of solute concentration, referring to the number of moles of solute per liter of solution

Question 15

Kinetic Energy

Answer 15

The energy associated with the relative motion of objects

Question 16

Mole (mol)

Answer 16

The number of grams of a substance that equals its molecular or atomic mass in daltons; a mole contains Avogadro’s number of the molecules or atoms in question

Question 17

Molecular Mass

Answer 17

The sum of the masses of all the atoms in a molecule; sometimes called molecular weight

Question 18

Ocean Acidification

Answer 18

Decreasing pH of ocean waters due to absorption of excess atmospheric CO2 from the burning of fossil fuels

Question 19

Polar Covalent Bond

Answer 19

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive

Question 20

Polar Molecule

Answer 20

A molecule (such as water) with and uneven distribution of charges in different regions of the molecule

Question 21

Surface tension

Answer 21

A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules

Question 21

Solvent

Answer 21

The dissolving agent of a solution. Water is the most versatile solvent known

Question 22

Solute

Answer 22

A substance that is dissolved in a solution

Question 23

Specific Heat

Answer 23

The amount of heat that must be absorbed or lost for 1 g of a substance to change its temperature by 1°C

Question 24

Temperature

Answer 24

A measure in degrees of the average kinetic energy (thermal energy) of the atoms and molecules in a body of water

Question 25

Thermal Energy

Answer 25

Kinetic energy due to the random motion of atoms and molecules; energy in its most random form