Properties Of Water Ch 3.2

Front 1

Four emergent properties of water making Earth suitable to sustain life

Back 1

Cohesion, Moderation of Temperature, Floating of Ice in Liquid, Solvent

Front 2

Cohesion

Back 2

A term for the result of many hydrogen bonds working together.
Contributes the transportation of water and dissolved nutrients against gravity to plant life.

Front 3

Water Conducting Cells

Back 3

Cells inside a plant that are resposible for carrying water from the ground up to leaves.
As water evaporates from a leaf the hydrogen bond from the leaving water molecule pulls on the molecules further inside the plant pulling up water molecules like a chain through the plant by way of the plants water conducting cells.

Front 4

Adhesion

Back 4

The clinging of one substance to another.
Aides the plant in the process of pulling water up against gravity by allowing the hydrogen bonds to bond also to the Cell wall.

Front 5

surface tension

Back 5

A measure of how difficult it is to stretch or break the surface of a liquid.
This is caused by the molecules on the surface of the water being hydrogen bonded to each other and those molecules below them. It seems as though there were a film on the water.

Front 6

How does water moderate air temperature?

Back 6

By absorbing heat from air that is warmer and releasing the stored heat into air that is cooler.
It can absorb a large amount of heatwl little difference to it's own temperature.

Front 7

kinetic energy

Back 7

The energy of motion/molecules are always moving
The faster the movement, the more kinetic energy

Front 8

thermal energy

Back 8

kinetic energy associated with the random movement of atoms andlor molecules.

Front 9

True of False: thermal energy and temperature are the same thing.

Back 9

False: Temperature is a measure of energy that represents an AVERAGE kinetic energy of the molecules is a body of matter regardless of volume, While thermal energy is the Total thermal energy that depends in Part on the matters volume,

Front 10

Give an example of thermal energy

Back 10

The liquid in a coffee pot that was just made has a higher temperature but less thermal energy than the liquid in a swimming pool

Front 11

What happens when liquids of different temperatures are brought together?

Back 11

The cooler liquid uses some of the thermal energy from the warmer liquid and it's molecules speed up.

Front 12

heat

Back 12

The transfer of themal energy from one body of matter to another.

Front 13

Calorie (cal)

Back 13

A unit of heat1 the amount of energy it takes to raise the temperature of lgram of water by l degree Celsius or that lgram of water releases when it cools.

Front 14

Kilocalorie (kcal)

Back 14

1,000 calories / the quantity of heat required to raise the temperature of) kilogram of water by l degree Celsius.
The "calories" on food packages are actually kilocalories.

Front 15

joules (J)

Back 15

Equals. 239 calories and I calorie equals 1 joule.

Front 16

specific heat

Back 16

the amount of heat that must be absorbed or lost for 1 gram of that to change it's temperature by 1 degree Celsius.

Front 17

what allows water to stabilize water so effectivel?

Back 17

Its high specific heat which is l calorie Per gram degree Celsius. This is unusually high.

Front 18

Specific heat of alcohol?

Back 18

.6 calories per gram degrees Celsius (ethyl alcohol)

Front 19

What is responsible for waters high specific heat?

Back 19

Hydrogen Bonding is responsible for the High specific heat of Water.
Heat must be absorbed tobreak hydrogen bonds and heat is lost when hydrogen bonds are formed. This means that most of the heat water absorbed is used in the process of breaking hydrogen bonds instead of heating the liquid.

Front 20

How specific heat effects life on earth

Back 20

Waters high specific heat allows it to absorb a lot of heat from the sun in the summer and the rating of water releases heat during the winter helping to moderate air temperature in coastal area's
waters high specific heat also Stabilizes ocean temperatures for the benifit of marine life.
Organisms made up of water (like humans) are more capable of regulating changes in their own temperature.

Front 21

evaporative cooling

Back 21

the cooling of the surface of a liquid as some evaporates taking away the fastest moving (highest kinetic energy) molecules.
The fastest molecules in a liquid move to quickly to bond and can escape the liquid. What results is a gas through a process called evaporation or vaporization.
A-small amount of liquid evaporates at any temperature as some of the molecules will be moving faster than the rest and will therefore be released as a gas.

Front 22

Heat of Vaporization

Back 22

An emergent property of water: The quantity of heat a liquid must absorb for 9-gram of it to be converted from the liquid to the gaseous state.
water has a high heat of uaporation due to it also having a high specific heat as a result of the strength of hydrogen bonds which have to be broken and can only be broken through heat.
The amount of heat it takes to evaporate 1-gram of water is 580 calories
580 calories per gram is nearly double that of alcohol or ammonia.

Front 23

How does evaporative cooling contribute to the stability of Earth?

Back 23

Evaporative cooling of water helps Keep lakes and ponds at a stable Temperature and provides a mechanism that prevents terrestrial organisms from overheating.

Front 24

Give an example of helpful evaporative cooling.

Back 24

Helps to keep terrestrial creates from overheating: Leaves remain cool despite the sun due to water evaporating from the surface of the leaf
sweat evaporating from our skin helps to keep us cool

Front 25

why is high humidity uncomfortable?

Back 25

High humidity is uncomfortable because of the high Concentration of water vapor in the air preventing the sweat on our skin to evaporate and contribute to cooling.

Front 26

Floating of Ice on water

Back 26

water is one of the few substances that is less dense as a solid than a liquid because as water freezes it expands instead of contracting and becoming more dense.

Front 27

What causes water to expand upon freezing?

Back 27

Once again, water is able to expand upon freezing rather then contracting because of hydrogen bonds.
AS the liquid ads it becomes to cold to break hydrogen bonds and they become formed into crystalline lattice (each molecule bonded to 4 others.) This bonding to 4 other molecules Keeps the molecules pushing on each other and equals expansion.

Front 28

How much less dense is ice than water

Back 28

Ice is 10% less dense than water (10% fewer molecules for the same volume)

Front 29

When is water at it's most dense?

Back 29

Water is it's most dense at 4 degrees Celsius.

Front 30

How does Ice floating contribute to Earth stability?

Back 30

If ice were more dense than water it would sink and eventually all ponds and lakes would freeze then eventually the ocean would even freeze rendering life on Earth impossible.
In the summer, only a few feet on the surface of the lake would unfreeze
Instead, ice floats and actually helps to insulate the liquid water below from temperature changes.
the solid ice also provides a surface for some animals like polar bears.

Front 31

what causes global warming?

Back 31

Carbon dioxide and other greenhouse gases in the atmosphere are having an effect on the environment by effecting icy environments around the globe.

Front 32

How much has the temperature in the arctic risen since 1961?

Back 32

1.4 degrees Celsius

Front 33

How has global temperature increase affected seasonal balance?

Back 33

The temperature increase has affected Arctic sea ice and liquid water causing ice to form later in the year and thaw earlier and to cover a Much smaller area.
The rate that glaciers and Artic sea ice are dissapearing is posing an extreme challenge for animals (line polar bears) that need ice to survive.

Front 34

Homogenous Mixture

Back 34

When the material dissolves completely in a liquid and results in having the same concentration everywhere in the solvent.

Front 35

Solution

Back 35

A completely homogenous mixture of two or more substances.

Front 36

Solvent

Back 36

the dissolving agent of a solution

Front 37

solute

Back 37

The substance that is dissolved by the solvent.

Front 38

aqeous solution

Back 38

A solution in which a solute is dissolved in water.

Front 39

Water as a Solvent

Back 39

Water is a versatile solvent which is a quality we can trace to the polarity of the water molecule.

Front 40

Give an example of water as a solvent

Back 40

A tablespoon of table salt or sodium chloride (NaCl) has all sodium and chloride ions at the surface is exposed to the solvent.Some regions of the solvent and the ions in the salt attract each other and due to their opposite chargeS, The oxygen regions are negatively charged and attracted to sodium cations and the hydrogen regions are positiudy charged and attracted to chloride ions. Resulting in the water molecules surrounding the individual sodium and chloride ions separating and shielding them from one another.

Front 41

Hydration shell

Back 41

The sphere of water that surrounds the dissolved ions that eventually dissolves all the ions.

Front 42

True or False: A compound has to be ionic to be dissolved in water.

Back 42

False: non-ionic polar molecules such as sugar are dissolvable in water. Water surrounds the non-ionic compounds just like the ionic compounds and dissolves them forming hydrogen bonds.

Front 43

True or False: Large ions can be dissolved in water.

Back 43

True: Even proteins will dissolve in water if they have ionic and polar regions on their surface.
Many polar compounds are dissolved in the water of biological fluids such as blood, sap of plants and liquid within a cell.

Front 44

Hydrophilic

Back 44

Any substance that has an affinity for water.

Front 45

True or False: A Compound has to dissolve in water to be called hydrophilic.

Back 45

False: Some substances can be hydrophilic without actually dissolving as in the case of molecules inside a cell that are solagelhey don't dissolve.
Cotton is another hydrophilic compound that does not dissolve as it consists of giant molecules of cellulose which is a compound with numerous regions of partial positive and partial negative charges that Can form hydrogen bonds with water. water adheres to the cellulose fibers which is why a cotton towels dries skin so well yet does not dissolve in the washing machine. cellulose is present in the cell wall of plants which is what contributes to the adhesion that takes place to allow plants to pull water from the ground.

Front 46

What hydrophilic compound is found in plant cell walls that allows for hydrogen bonds with water?

Back 46

Cellulose is a hydrophilic compound found in the cell walls of plants. The cellulose present in the cell wall aides the plant in pulling water from the ground up to the leaves with hydrogen bonds.

Front 47

Hydrophobic

Back 47

Substances that do not have an affinity for water like non polar and nonionic compounds that cannot form hydrogen bonds. These actually seem to repel water.

Front 48

Give examples of hydrophic compounds.

Back 48

Vegetable oil which does not mix stably with water-based substances such as vinegar.
Oil have a prevalence of relatively non polar covalent bonds, in this casebetween carbon and hydrogen which share electrons almost equally.
the hydrophobic molecules here are mainly major ingredients in the cell membranes which if dissolved would result in death.

Front 49

what is the most important solute for chemical reactions in organisms?

Back 49

Themost important solute for chemical reactions in an organism is water. To understand these chemical reactions we need to know how many atoms are in each and calculate concentrations of solutes in an aqueous Solution. (The number of solute molecules in a volume of solution)

Front 50

What must you Know in ordo to calculate the number of molecules during experimentation?

Back 50

Mass must be Known. the first tking we calculate is Molecular Mass.

Front 51

Molecular Mass

Back 51

the sum of the masses of all the atoms in a molecule.
Table Sugar (sucrose) molecular mass: c 12 H 22 O11 the mass of Carbon atom is 12, Hydrogen atomist and Oxygen 16 thus the formula for it's molecular MASS is: (12*12) + (22× 1) + (11 × 16) = 342 Daltons

Front 52

Moles

Back 52

Moles are the unit with which we measure substances because the small actual numbers of molecules are impossible to measure.
A Mole (mol) represents an exact number of objects 6.02 X 10 to the twenty third power

Front 53

Avogadro's Number

Back 53

the exact number that are represented by the term mole.

Front 54

How many Daltons in 1 gram?

Back 54

Becaus of the way moles and Daltons were defined there are 6.02 × 10 to the 23rd Daltons in lgram.

Front 55

molar mass

Back 55

After the molecular mass has been determined we can use the same number but with the unit grams to represent the mass of 6.02 × 10 to the 23 rd molecules of sucrose. To obtain lmolof Sucrose in the lab you weigh 342grams of Sucrose.