Water and the Fitness of the Environment

Question 1

is the biological medium on Earth

Answer 1

Water

Question 2

All living organisms require this more than
any other substance

Answer 2

water

Question 3

Most cells are surrounded by water, and cells
themselves are about how many percetage of water?

Answer 3

70–95% water

Question 4

The abundance of water is the main reason the
Earth is

Answer 4

habitable

Question 5

The water molecule is what kind of molecule?

Answer 5

polar molecule

Question 6

it is when the
opposite ends have opposite charges

Answer 6

polar molecule

Question 7

it allows water molecules to form
hydrogen bonds with each other

Answer 7

Polarity

Question 8

5 what are the properties of water

Answer 8

High specific heat
High heat of vaporization
Unique density behavior
High Surface Tension
An excellent solvent

Question 9

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

Answer 9

specific heat

Question 10

what is the specific heat of water

Answer 10

1 cal/g/*C

Question 11

Water resists changing its temperature
because of its

Answer 11

high specific heat

Question 12

a measure of
temperature using Celsius degrees (°C)

Answer 12

Celsius scale

Question 13

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

Answer 13

calorie (cal)

Question 14

The “calories” on food packages are actually

Answer 14

kilocalories (kcal)

Question 15

where 1 kcal =

Answer 15

1,000 cal

Question 16

is another unit of energy where
1 J = 0.239 cal, or 1 cal = 4.184 J

Answer 16

joule (J)

Question 17

what is 1 cal into joules

Answer 17

4.184 J

Question 18

is heat being absorbed or released when hydrogen bonds break?

Answer 18

Heat is absorbed

Question 19

is heat being absrobed or released when hydrogen bonds form

Answer 19

Heat is released

Question 20

what property of water minimizes
temperature fluctuations to within limits that
permit life

Answer 20

high specific heat of water

Question 21

it is the energy of motion

Answer 21

Kinetic energy

Question 22

it is a measure of the total amount of kinetic
energy due to molecular motion

Answer 22

Heat

Question 23

it measures the intensity of heat
due to the average kinetic energy of molecules

Answer 23

Temperature

Question 24

Water absorbs heat from warmer air and
releases stored heat to

Answer 24

cooler air

Question 25

Water can absorb or release a large amount of heat with only a

Answer 25

slight change in its own temperature

Question 26

is transformation of a substance from liquid to gas

Answer 26

Evaporation

Question 27

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

Answer 27

Heat of vaporization

Question 28

As a liquid evaporates, its remaining surface cools, a process called

Answer 28

evaporative cooling

Question 29

this process helps stabilize temperatures in organisms and bodies of water

Answer 29

Evaporative cooling of water

Question 30

Collectively, hydrogen bonds hold water molecules together, a phenomenon

Answer 30

cohesion

Question 31

helps the transport of water against gravity in plants

Answer 31

Cohesion

Question 32

is an attraction between different substances, for example, between water and plant cell walls

Answer 32

Adhesion

Question 33

here, Hydrogen bonds are stable

Answer 33

ice

Question 34

here, Hydrogen bonds break and re-form

Answer 34

Liquid water

Question 35

is a measure of how hard it is to break the surface of a liquid

Answer 35

Surface tension

Question 36

is related to cohesion

Answer 36

Surface tension

Question 37

is a liquid that is a homogeneous mixture of substances

Answer 37

solution

Question 38

is the dissolving agent of a solution

Answer 38

solvent

Question 39

is the substance that is dissolved

Answer 39

solute

Question 40

is one in which water is the solvent

Answer 40

aqueous solution

Question 41

is a versatile solvent due to its polarity, which allows it to form hydrogen bonds easily

Answer 41

Water

Question 42

When an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules called

Answer 42

hydration shell

Question 43

Water can also dissolve compounds made of what kind of polar molecules

Answer 43

nonionic polar molecules

Question 44

what example of polar molecule can dissolve in water if they haev ionic and polar regions

Answer 44

proteins

Question 45

substance is one that has an affinity for water

Answer 45

hydrophilic

Question 46

substance is one that does not have an affinity for water

Answer 46

hydrophobic

Question 47

what molecule is an example of hydrophobic because they have relatively nonpolar bonds

Answer 47

Oil molecules

Question 48

is a stable suspension of fine particles in a liquid

Answer 48

colloid

Question 49

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

Answer 49

Molecular mass

Question 50

1 mole (mol) is equal to

Answer 50

6.02 x 1023 molecules

Question 51

what is avogadros number

Answer 51

6.02 x 1023 daltons

Question 52

what is the unit of avogadro's number

Answer 52

daltons

Question 53

is the number of moles of solute per liter of solution

Answer 53

Molarity (M)

Question 54

in a hydrogen bond between two water molecules can shift from one to the other:

Answer 54

hydrogen atom

Question 55

it is when The hydrogen atom leaves its electron behind and is transferred as a proton, or

Answer 55

hydrogen ion (H+

Question 56

it is when The molecule with the extra proton is now a -------- (H3O+), though it is often represented as H+

Answer 56

hydronium ion

Question 57

it is a molecule that lost the proton is now a

Answer 57

hydroxide ion (OH–)

Question 58

what state is a water in which water molecules dissociate at the same rate at which they are being reformed

Answer 58

equilibrium

Question 59

is any substance that increases the H+ concentration of a solution

Answer 59

acid

Question 60

is any substance that reduces the H+ concentration of a solution

Answer 60

base

Question 61

the ---- of a solution is defined by the negative logarithm of H+ concentration, written as pH = –log [H+]

Answer 61

pH of water

Question 62

what is the constant of aqueous solution

Answer 62

[H+ ][OH–] = 10^–14

Question 63

what is the constant For a neutral aqueous solution

Answer 63

[H+] is 10^–7 = –(–7) = 7

Question 64

helps to describe whether a solution is acidic or basic (the opposite of acidic)

Answer 64

pH scale

Question 65

have pH values less than 7

Answer 65

Acidic solutions

Question 66

have pH values greater than 7

Answer 66

Basic solutions

Question 67

have pH values in the range of 6 to 8

Answer 67

Most biological fluids

Question 68

The internal pH of most living cells must remain close to pH

Answer 68

7

Question 69

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

Answer 69

Buffers

Question 70

refers to rain, snow, or fog with a pH lower than 5.6

Answer 70

Acid precipitation

Question 71

is caused mainly by the mixing of different pollutants with water in the air and can fall at some distance from the source of pollutants

Answer 71

Acid precipitation

Question 72

Acid precipitation can damage life in

Answer 72

lakes and streams

Question 73

----- such as burning fossil fuels threaten water quality

Answer 73

Human activities

Question 74

A warming of earth called the

Answer 74

“greenhouse” effect

Question 75

this leads to a decrease in the ability of corals to form calcified reefs

Answer 75

Acidification of the oceans;

Question 76

is released by fossil fuel combustion and contributes to the “greenhouse” effect and Acidification of the oceans

Answer 76

CO2

Question 77

donate H+ in aqueous solutions

Answer 77

Acids

Question 78

donate OH– or accept H+ in aqueous solutions

Answer 78

Bases