2.2 Water

Question 1

What are the properties of water?

Answer 1

excellent solvent
high heat capacity & vaporization
low ice density
cohesive and adhesive properties
helps maintain homeostasis

Question 2

Define hydrophillic

Answer 2

water forms hydrogen bonds with polar molecules, ions and water
water loving

Question 3

define hydrophobic

Answer 3

non-polar molecules ex. oils and fats
water fearing

Question 4

What occurs in liquid water?

Answer 4

hydrogen bonds constantly form and break as water molecules move

Question 5

What is kinetic energy?

Answer 5

motion of water due to heat in the system

Question 6

How do water molecules react in steam and water vapor?

Answer 6

They move quickly= higher kinetic energy- more heat

Question 7

What occurs in ice?

Answer 7

temp less= no kinetic energy= less movement- stationary hydrogen bonds

Question 8

Why does ice have low density?

Answer 8

due to water molecules being pushed farther apart compared to liquid molecules- bonds are not moving & changing

Question 9

Why are other liquids different from water?

Answer 9

they pack even more compared to water due to less kinetic energy- more density

Question 10

How does ice benefit organisms?

Answer 10

Ice on lakes act as an insulating barrier; protects organisms in waters from freezing

Question 11

How would organisms react without this property of ice?

Answer 11

They would freeze due to the expansion of ice and ice crystals would rupture delicate membranes of cells need for life

Question 12

What caused water’s high heat capacity?

Answer 12

caused by hydrogen bonding

Question 13

what is specific heat?

Answer 13

the amount of heat one gram of a substance must absorb or lose to change its temperature 1*C

Question 14

What is the specific heat for water?

Answer 14

1 calorie; takes a long time to cool and heat
compared to land

Question 15

How is water high heat capacity beneficial for organisms?

Answer 15

water is used to disperse heat in warm-blooded animals- transports heat from warm places to cool

Question 16

Define water’s high heat of vaporization

Answer 16

the amount of energy to change 1 g of a liquid to gas- 569 calorie

Question 17

What is the process of water’s vaporization?

Answer 17

water heats- difficult for water to separate due to hydrogen bonding

Question 18

WHat is a heat sink or heat reservoir?

Answer 18

unable to heat up quickly

Question 19

evaporization

Answer 19

surface molecules escape and vaporize causing the heat to go away and the environment to cool

Question 20

How does water’s high heat vaporization help in organisms?

Answer 20

evaporation of sweat- cooling- homeostasis

Question 21

Why does water have amazing solvent properties

Answer 21

due to its polar covalent properties and sphere of hydration

Question 22

What is the sphere of hydration?

Answer 22

surrounding a particle with hydrogen bonds from water molecules to keep particles in water

Question 23

What is disassociation

Answer 23

when ionic compounds are added to water, the individual ions react with polar regions of water molecules, and ionic bonds are disrupted
It occurs when atoms or a group break off from molecules to form ions

Question 24

Define cohesion

Answer 24

water makes dome shape; water molecules attract each other which keeps them together even when there’s no more room

Question 25

define surface tension

Answer 25

capacity of a substance to withstand rupture under tension; (placing a needle)

Question 26

define adhesion

Answer 26

attraction between water molecules and other molecules; stronger than cohesion sometimes

Question 27

capillary actionw

Answer 27

water climbs on the side of the tube- charged glass walls

Question 28

How is water’s cohesive and adhesive properties used in organisms?

Answer 28

transport water from roots to leaves
insects float on water

Question 29

What is limitus

Answer 29

ph paper- pH indicator

Question 30

What are buffers

Answer 30

absrobs excess H+ and OH- to maintain pH for survival

Question 31

What are the buffers of blood?

Answer 31

carbonic acid, bicarbonate ion and CO2 and antacids