Water and the Fitness of the Environment

Question 1

cohesion

Answer 1

hydrogen bonds hold the substance together

Question 2

adhesion

Answer 2

clinging of one substance to another

Question 3

surface tension

Answer 3

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

Question 4

heat

Answer 4

measure of the total amount of kinetic energy due to melecular motion in a body of matter

Question 5

temperature

Answer 5

measures the intesity of heat due to the average kinetic energy of molecules

Question 6

calorie

Answer 6

the amount of heat it takes to raise the temperature of 1g of water by 1°C

Question 7

specific heat

Answer 7

The specific heat of a substance is defined as the amount of heat that must be absorbed or lost for 1g of that substance to change its temperature by 1°C.

Question 8

heat of vaporization

Answer 8

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

Question 9

evaporative cooling

Answer 9

Evaporative cooling occurs beacause the “hottest” molecules, those with the greatest kinetic engergy, are the most likely to leave as gas.

Question 10

solution

Answer 10

A liquid that is completely homogeneous mixture of two or more substances is called solution.

Question 11

solvent; solute

Answer 11

The dissolving agent of a solution is the solvent and the substance that is dissolved the solute.

Question 12

aqueous solution

Answer 12

one in which water is the solvent

Question 13

hydration shell

Answer 13

The sphere of water molecules around each dissolved ion is called hydration shell.

Question 14

hydrophilic

Answer 14

any substance that has an affinity for water

Question 15

colloid

Answer 15

a stable suspension of fine particles in a liquid

Question 16

hydrophobic

Answer 16

substances that are nonionic and nonpolar actually seems to repel water

Question 17

molecular mass

Answer 17

the sum of the masses of all the atoms is a molecule

Question 18

mole

Answer 18

an exact number of objects

Question 19

Avogado’s number

Answer 19

6.02 * 10²³

Question 20

molarity

Answer 20

number of moles of solute per liter of solution; unit of concentration

Question 21

acid

Answer 21

a substance that increases the hydrogen ion concentration of a solution

Question 22

base

Answer 22

substance that reduces the hydrogen ion concentration of a solution

Question 23

buffers

Answer 23

substances that minimize changes in the concentrations of H⁺ and OH^- in a solution

Question 24

Pufferkapazität

Answer 24

die Menge einer Säure/ Base, die zugegeben werden muss, um den pH- Wert von 1l der Üufferlösung um eine Einheit zu ändern.