Biology Chp 3

Question 1

Four Emergent Properties of Water

chp 3

Answer 1

Cohesion, moderation of temp, expansion upon freezing, versatility as a solvent

Water is the only substance to exist in natural environment in all three physical states of matter

Question 2

Polar covalent bonds

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Answer 2

e- spend more time closer to the higher electronegative atoms

Question 3

Polar molecule

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Answer 3

unequal sharing of e-, overall charge unequally distributed

Question 4

Cohesion

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Answer 4

hydrogen bonds hold a substance together.
- Contributes to the transport of water and dissolved nutrients in plants

Question 5

Surface tension

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Answer 5

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

Question 6

Adhesion

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Answer 6

the clinging of one substance to another.
- Contributes to transport of water and dissolved nutrients in plants

Question 7

Kinetic Energy

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Answer 7

the energy of motion

atoms and molecules have kinetic energy

Question 8

Thermal energy

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Answer 8

the kinetic energy accociated with the random movement of atoms or molecules.
- reflects total kinetic energy -> depends on matter’s volume

Question 9

Temperature

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Answer 9

represents the average kinetic energy of the molecules in a body of matter, regardless of volume

passes from warmer to cooler object

Question 10

Heat

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Answer 10

Thermal energy in transfer from one body of matter to another

Question 11

Calorie (cal)

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Answer 11

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

Also the amount of heat water releases when lowering in temp

Question 12

Kilocalorie (1,000cal)

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Answer 12

quantity of heat required to raise the temp of 1kg of water by 1° C

Question 13

Joule (J)

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Answer 13

1 J = 0.239cal ; 1cal = 4.184 J

Question 14

Specific Heat

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Answer 14

the amount of heat that must be absorbed or lost for 1g of that substance to change its temp by 1° C.
- HIgher specific heat means less temperature change

The specific heat of H20 = 1cal/(g°C)

Question 15

Vaporization/Evaporation

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Answer 15

when molecules move fast enough to overcome attractions keeping them together

higher heat = greater evaporation

Question 16

Heat of vaporization

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Answer 16

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

Question 17

Evaporative cooling

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Answer 17

as a liquid evaporates, the surface of the liwuid that remains behind cools down

Question 18

Floating Ice on Liquid Water

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Answer 18

H20 is less dense as a solid
- due to h-bonding
- floating ice allows for marine life

Question 19

Solution

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Answer 19

completely homogenous mixture of 2 or more substances

Question 20

Solvent

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Answer 20

dissolving agent in a solution

Question 21

Aqueous solution

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Answer 21

solution in which solute is dissolved in water

Question 22

Solute

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Answer 22

substance that is dissolved

Question 23

Hydration shell

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Answer 23

sphere of h20 molecules around each dissolved ion

Question 24

Hydrophilic

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Answer 24

any substance that has an affinity for water

Question 25

Hydrophobic ## Footnote chp 3

Answer 25

substances that repel H2O ## Footnote major ingredients in cell membranes

Question 26

Molecular mass ## Footnote chp 3

Answer 26

sum of the masses of all the atoms in a molecule

Question 27

mole (mol) ## Footnote chp 3

Answer 27

unit used to measure substances. - sometimes called molar mass

Question 28

Molarity ## Footnote chp 3

Answer 28

the number of moles of solute per liter of solution

Question 29

Hydroxide Ion (OH-) ## Footnote chp 3

Answer 29

The result of a water molecule losing a proton (H+). has a negative charge

Question 30

Hydronium Ion ## Footnote chp 3

Answer 30

The result of the proton from another water molecule binding to another H20 molecule, making it H3O+ | H+ often represents H3O+

Question 31

Dissociation of Water ## Footnote chp 3

Answer 31

- Statistically rare - reversible reaction

Question 32

Acid ## Footnote chp 3

Answer 32

a substance that increases the hydrogen ion concentration [H+] of a solution

Question 33

Base ## Footnote chp 3

Answer 33

a substance that reduces the hydrogen ion concentration of a solution

Question 34

Neutral Solutions ## Footnote chp 3

Answer 34

[H+] = [OH-]

Question 35

Weak Acids ## Footnote chp 3

Answer 35

acids that reversibly release and accept back hydrogen ions ## Footnote Carbonic Acid

Question 36

pH of any aqueous solution ## Footnote chp 3

Answer 36

In any aqueous solution at 25° C, the product of the H+ and OH- concentrations is constant at 10^-14 | Can be written as [H+][OH-] = 10^-14 [H+] = 10^-7 [OH-] = 10^-7 ## Footnote brackets indicate molar concentration

Question 37

pH ## Footnote chp 3

Answer 37

the negative logarithim(base 10) of the H+ concentration. - Higher pH is more basic while lower pH is more acidic ## Footnote pH = -log[H+] internal pH of most living cells must stay close to pH=7

Question 38

Buffers ## Footnote chp 3

Answer 38

A substance that minimizes changes in the concentrations of H+ and OH- in a solution - accepts hydrogen ions from the solution when they are in excess and donates hydrogen ions when they have been depleted ## Footnote Most contain a weak acid and it's corresponding base One of the buffers that contributes to pH stability in blood is carbonic acid (H2CO3) which is formed when CO2 reacts with H2O in blood plasma

Question 39

Ocean acidification ## Footnote chp 3

Answer 39

when CO3 dissolves in dea water, reacting with H2O to form carbonic acid, which lowers ocean pH