1.1/2.5 water and the fitness of the environment

Question 1

hydrogen bond definition

Answer 1

O- bonds with H+ on a different molecule of H2O

Question 2

how many bonds can H2O form?

Answer 2

4

Question 3

cohesion definition

Answer 3

polar H-bonding between like molecules

Question 4

surface tension definition

Answer 4

measure of difficulty to break or stretch surface of liquid (H-bonding)

Question 5

adhesion definition

Answer 5

H-bonding between unlike molecules

Question 6

how does adhesion of water to vessel walls work?

Answer 6

Adhesion of H2O to vessel walls counters downward pull of gravity

Question 7

transpiration definiton

Answer 7

movement of H2O up plants

Question 8

how does water move up plants?

Answer 8

H2O clings to each other by cohesion; cling to xylem tubes by adhesion

Question 9

heat definition

Answer 9

total amount of KE in system

Question 10

temperature definition

Answer 10

measure intensity of heat due to average KE of molecules

Question 11

water’s high specific heat:

Answer 11

Change temp less when absorbs/loses heat
Large bodies of water absorb and store more heat/energy → warmer coastal areas
Create stable marine/land environment
Humans ~65% H2O → stable temp, resist temp. change
H-bonding

Question 12

evaporative cooling

Answer 12

Water has high heat of vaporization
Molecules with greatest KE leave as gas
Stable temp in lakes & ponds
Cool plants
Human sweat
liquid –> gas

Question 13

insulation by ice

Answer 13

less dense, floating ice insulates liquid H2O below

Question 14

solution

Answer 14

liquid, homogeneous mixture of 2+ substances

Question 15

solvent

Answer 15

dissolving agent (liquid)

Question 16

what’s the best versatile solvent?

Answer 16

water

Question 17

solute

Answer 17

dissolved substance

Question 18

hydrophilic solvents

Answer 18

affinity for H2O
polar, ions
cellulose, sugar, salt
blood

Question 19

hydrophobic solvents

Answer 19

repel H2O
nonpolar
oils, lipids
cell membrane

Question 20

hydronium ion production

Answer 20

H+ + H2O –> H3O+

Question 21

hydroxide ion production

Answer 21

H2O - H+ –> OH-

Question 22

acid definition

Answer 22

increases [H+]

Question 23

base definition

Answer 23

reduces [H-]

Question 24

what pH are most biological fluids?

Answer 24

6-8

Question 25

pH =

Answer 25

-log [H+]

Question 26

calculating pH formula

Answer 26

[H+][OH-] = 10^-14

Question 27

buffers definition

Answer 27

minimize changes in concentration of H+ and OH- in a solution (weak acids and bases)

Question 28

pH of blood

Answer 28

7.4 (about) - maintained by buffers

Question 29

deadly blood pH?

Answer 29

less than 7, over 7.8

Question 30

what are important buffers in blood plasma?

Answer 30

carbonic acid – bicarbonate system

Question 31

carbonic acid decomposition

Answer 31

H2CO3 (carbonic acid) –> HCO3- (bicarbonate) + H+

Question 32

CO2 + seawater

Answer 32

carbonic acid