Waterworks Operations IIWaterworks Operations II

Lecture 2

Water Properties/Chemistry

A Review

Lecture 2

Water Properties/Chemistry

A Review

http://www.mansfield.ohio-state.edu/~sabedon/biol1015.htm#hydrogen_bond

Key Words• Solute- The substance that dissolves to form a

solution • Solvent- substance in which another substance is

dissolved, forming a solution.• Solution- a medium consisting of solutes and

solvents• Hydration- formation of water molecules around

an ion. • Ions- electrically charged atoms • Cohesion- attraction of a water molecule to

another water molecule via hydrogen bonding• Adhesion- attraction of a water molecule to a non

water molecule

• Solute- The substance that dissolves to form a solution

• Solvent- substance in which another substance is dissolved, forming a solution.

• Solution- a medium consisting of solutes and solvents

• Hydration- formation of water molecules around an ion.

• Ions- electrically charged atoms • Cohesion- attraction of a water molecule to

another water molecule via hydrogen bonding• Adhesion- attraction of a water molecule to a non

water molecule

Substance in which another substance is dissolved, forming

a solution.

Solu

te

Solv

ent

Solu

tion

15% 15%

70%1. Solute

2. Solvent

3. Solution

1. Solute

2. Solvent

3. Solution

A medium consisting of solutes and solvents

Solu

te

Solv

ent

Solu

tion

9%

91%

0%

1. Solute

2. Solvent

3. Solution

1. Solute

2. Solvent

3. Solution

The substance that dissolves to form a solution

Solu

te

Solv

ent

Solu

tion

95%

5%0%

1. Solute

2. Solvent

3. Solution

1. Solute

2. Solvent

3. Solution

Cohesion is _________.

The

attra

ctio

n of o

ne...

invo

lves

the

attra

ctio

n...

Influ

ence

d by

wat

er b

...

All

of the

above

79%

21%

0%0%

1. The attraction of one water molecule to another resulting from hydrogen bonding

2. involves the attraction of a water molecule to a non-water molecule.

3. Influenced by water being a non polar molecule

4. All of the above

1. The attraction of one water molecule to another resulting from hydrogen bonding

2. involves the attraction of a water molecule to a non-water molecule.

3. Influenced by water being a non polar molecule

4. All of the above

Sublimation is the phase change as a substance changes from a solid to a gas without passing through the intermediate state of a liquid. Triple POINT - The temperature and pressure at which the solid, liquid, and gas phases exist simultaneously.

273.16 K (0.01 oC) and a pressure of 611.73 pascals (ca. 6.1173 millibars, 0.0060373057 atm).

Critical POINT - The temperature above which a substance will always be a gas regardless of the pressure.

around 647 oK (374 oC or 705 oF) and 22.064 MPa (3200 PSIA or 218 atm).

Freezing Point - The temperature at which the solid and liquid phases of a substance are in equilibrium at atmospheric pressure. Boiling Point - The temperature at which the vapor pressure of a liquid is equal to the pressure on the liquid. Normal (Standard) Boiling Point - The temperature at which the vapor pressure of a liquid is equal to standard pressure (1.00 atm = 760 mmHg = 760 torr = 101.325 kPa)

Sublimation is the phase change as a substance changes from a solid to a gas without passing through the intermediate state of a liquid. Triple POINT - The temperature and pressure at which the solid, liquid, and gas phases exist simultaneously.

273.16 K (0.01 oC) and a pressure of 611.73 pascals (ca. 6.1173 millibars, 0.0060373057 atm).

Critical POINT - The temperature above which a substance will always be a gas regardless of the pressure.

around 647 oK (374 oC or 705 oF) and 22.064 MPa (3200 PSIA or 218 atm).

Freezing Point - The temperature at which the solid and liquid phases of a substance are in equilibrium at atmospheric pressure. Boiling Point - The temperature at which the vapor pressure of a liquid is equal to the pressure on the liquid. Normal (Standard) Boiling Point - The temperature at which the vapor pressure of a liquid is equal to standard pressure (1.00 atm = 760 mmHg = 760 torr = 101.325 kPa)

Key Words

The phase change as a substance changes from a solid to a gas without

passing through the intermediate state of a liquid.

Sublim

atio

n

Fre

ezin

g poin

t

Crit

ical

poin

t

Boili

ng poin

t

93%

4%0%4%

1. Sublimation

2. Freezing point

3. Critical point

4. Boiling point

1. Sublimation

2. Freezing point

3. Critical point

4. Boiling point

The temperature above which a substance will always be a gas

regardless of the pressure.

Trip

le P

oint

Crit

ical

Poin

t

Fre

ezin

g poin

t

Boili

ng poin

t

0% 0%0%

100%1. Triple Point

2. Critical Point

3. Freezing point

4. Boiling point

1. Triple Point

2. Critical Point

3. Freezing point

4. Boiling point

WaterWater•Water covers 70-80% of earths surface

•97% of earth’s water in the oceans!

•3% freshwater

•98% of the 3% of freshwater that is used as drinking water is groundwater!

•Water covers 70-80% of earths surface

•97% of earth’s water in the oceans!

•3% freshwater

•98% of the 3% of freshwater that is used as drinking water is groundwater!

What percentage of the water used in the United States comes

from underground sources?

What percentage of the water used in the United States comes

from underground sources?

45%

30%

60%

90%

28%

22%22%

28%

1. 45%

2. 30%

3. 60%

4. 90%

1. 45%

2. 30%

3. 60%

4. 90%

Nearly 95 percent of the rural population of the US relies on

ground water.

Tru

e

Fal

se

0%

100%1. True

2. False

1. True

2. False

WaterWater•Life evolved in water, ~70% human body

•Centigrade scale (0oC freeze) based on (100oC boil) water prop.

•Most common molecule that exists as a liquid at ambient temperatures

•Unique properties

high polarity, hydrogen bonding, cohesion, adhesion. high specific heat, high heat of vaporization, polar

solvent

•Life evolved in water, ~70% human body

•Centigrade scale (0oC freeze) based on (100oC boil) water prop.

•Most common molecule that exists as a liquid at ambient temperatures

•Unique properties

high polarity, hydrogen bonding, cohesion, adhesion. high specific heat, high heat of vaporization, polar

solvent

Which of the following is true about water?

Which of the following is true about water?

Univ

ersa

l sol

vent

Hig

h hea

t cap

acity

Hig

h hea

t of v

apor

iz...

Liq

uid ra

ther

then

a g

..

All

of the

above

0% 0%

100%

0%0%

1. Universal solvent

2. High heat capacity

3. High heat of vaporization

4. Liquid rather then a gas at room temperature

5. All of the above

1. Universal solvent

2. High heat capacity

3. High heat of vaporization

4. Liquid rather then a gas at room temperature

5. All of the above

WaterWater•Structure–Tetrahedral (arrangement of electrons)

• two hydrogen's (positive)• One oxygen (negative)• (O) two non-bonding electron pairs

•Polar molecule–partial + (H) at one end, –partial – (O) at the other end

• excellent solvent

•Structure–Tetrahedral (arrangement of electrons)

• two hydrogen's (positive)• One oxygen (negative)• (O) two non-bonding electron pairs

•Polar molecule–partial + (H) at one end, –partial – (O) at the other end

• excellent solvent

+

+

-

104.5°

Water is a polar molecule ?Water is a polar molecule ?

Tru

e

Fal

se

0%

100%1. True

2. False

1. True

2. False

Water (hydrogen bonding)Water (hydrogen bonding)hydrogen bond : bonding between oxygen and

hydrogen (not strong)-Weak individually, stronger in larger quantities.

Hydrogen bonding is responsible for:

- liquid rather then gas at room temp

- high specific heat, heat of vaporization

- universal solvent

- adhesion

-cohesion- sticks together = liquid instead of changing to gas

hydrogen bond : bonding between oxygen and hydrogen (not strong)

-Weak individually, stronger in larger quantities.

Hydrogen bonding is responsible for:

- liquid rather then gas at room temp

- high specific heat, heat of vaporization

- universal solvent

- adhesion

-cohesion- sticks together = liquid instead of changing to gas

Water (High Specific Heat)Water (High Specific Heat)Specific Heat- The amount of heat needed to raise the

temperature of one gram of a substance by 1°C.

-a temperature increase is an increase in the motion of the molecules and atoms making up a substance.

water molecules resist increasing their motion. (this is another way of saying that is water molecules resist the net breaking of hydrogen bonds)

water resists heating; water has a very high specific heat.

Specific Heat- The amount of heat needed to raise the temperature of one gram of a substance by 1°C.

-a temperature increase is an increase in the motion of the molecules and atoms making up a substance.

water molecules resist increasing their motion. (this is another way of saying that is water molecules resist the net breaking of hydrogen bonds)

water resists heating; water has a very high specific heat.

Water High Heat Vaporizationboiling

Water High Heat Vaporizationboiling

Heat of Vaporization- The amount of heat required to convert a unit mass of a liquid at its boiling point into vapor

Vaporization is the breaking of hydrogen bonds (water has a lot of hydrogen bonding)

water resists vaporizing (evaporating). Consequently, it takes a lot of heat to evaporate water.

Heat of Vaporization- The amount of heat required to convert a unit mass of a liquid at its boiling point into vapor

Vaporization is the breaking of hydrogen bonds (water has a lot of hydrogen bonding)

water resists vaporizing (evaporating). Consequently, it takes a lot of heat to evaporate water.

normal boiling point of 100 ºC, the latent specific latent heat of vaporization is 2260 kJ.kg-1. normal boiling point of 100 ºC, the latent specific latent heat of vaporization is 2260 kJ.kg-1.

Water High Latent Heat of Fusion melting

Water High Latent Heat of Fusion melting

Latent Heat of Fusion- the amount of heat required to convert a unit mass of the solid into the liquid without a change in temperature

Need to add a lot of energy to break apart hydrogen bonds.

Latent Heat of Fusion- the amount of heat required to convert a unit mass of the solid into the liquid without a change in temperature

Need to add a lot of energy to break apart hydrogen bonds.

Water has a heat of fusion of 143 Btu/lb. Water has a heat of fusion of 143 Btu/lb.

Which of the is responsible for water being a liquid rather then

gas at room temp?

Which of the is responsible for water being a liquid rather then

gas at room temp?

Hyd

roge

n bondi

ng

Hig

h hea

t cap

acity

Hig

h hea

t of v

apor

iz...

73%

23%

5%

1. Hydrogen bonding

2. High heat capacity

3. High heat of vaporization

1. Hydrogen bonding

2. High heat capacity

3. High heat of vaporization

The amount of heat required to convert a unit mass of the solid into the liquid without a change

in temperature?

The amount of heat required to convert a unit mass of the solid into the liquid without a change

in temperature?

Hyd

roge

n bondi

...

Spec

ific

Heat

Hea

t of v

apor

i...

Lat

ent H

eat o

f...

0%

33%33%33%

1. Hydrogen bonding

2. Specific Heat

3. Heat of vaporization

4. Latent Heat of Fusion

1. Hydrogen bonding

2. Specific Heat

3. Heat of vaporization

4. Latent Heat of Fusion

The amount of heat required to convert a unit mass of a liquid at

its boiling point into vapor ?

The amount of heat required to convert a unit mass of a liquid at

its boiling point into vapor ?

Hyd

roge

n bondi

ng

Spec

ific

Heat

Hea

t of v

apor

izatio

n

Lat

ent H

eat o

f Fusi

on

5% 0%

91%

5%

1. Hydrogen bonding

2. Specific Heat

3. Heat of vaporization

4. Latent Heat of Fusion

1. Hydrogen bonding

2. Specific Heat

3. Heat of vaporization

4. Latent Heat of Fusion

The amount of heat needed to raise the temperature of one

gram of a substance by 1°C?

The amount of heat needed to raise the temperature of one

gram of a substance by 1°C?

Hyd

roge

n bondi

ng

Spec

ific

Heat

Hea

t of v

apor

izatio

n

Lat

ent H

eat o

f Fusi

on

0% 0%0%

100%

1. Hydrogen bonding

2. Specific Heat

3. Heat of vaporization

4. Latent Heat of Fusion

1. Hydrogen bonding

2. Specific Heat

3. Heat of vaporization

4. Latent Heat of Fusion

Hydrochloric acid is a better

solvent then water ?Hydrochloric acid is a better

solvent then water ?

Tru

e

Fal

se

94%

6%

1. True

2. False

1. True

2. False

Heating/Cooling CurveHeating/Cooling Curve

Freezing is the phase change as a substance changes from a liquid to a solid. Melting is the phase change as a substance changes from a solid to a liquid. Condensation is the phase change as a substance changes from a gas to a liquid. Vaporization is the phase change as a substance changes from a liquid to a gas.

Freezing is the phase change as a substance changes from a liquid to a solid. Melting is the phase change as a substance changes from a solid to a liquid. Condensation is the phase change as a substance changes from a gas to a liquid. Vaporization is the phase change as a substance changes from a liquid to a gas.

0oC0oC

100oC100oC

A: Rise in temperature as ice absorbs heat.B: Absorption of latent heat of fusion.C: Rise in temperature as liquid water absorbs heat.D: Water boils and absorbs latent heat of vaporization.E: Steam absorbs heat and thus increases its temperature.

A: Rise in temperature as ice absorbs heat.B: Absorption of latent heat of fusion.C: Rise in temperature as liquid water absorbs heat.D: Water boils and absorbs latent heat of vaporization.E: Steam absorbs heat and thus increases its temperature.

Uptake of heat by 1 kg of water, as it passes from ice at -50 ºC to steam at temperatures above 100 ºC

Liquid

Gas

Solid

Water (Universal Solvent)Water (Universal Solvent)Water tends to very effectively dissolve

hydrophilic (water loving) substances Water tends to very effectively dissolve

hydrophilic (water loving) substances

Phil Lesh

Water

• Solvent– high polarity

– good solvent for polar (salt) compounds

• Solvent– high polarity

– good solvent for polar (salt) compounds

salts and solids solubilityZClO4, ZNO3 all Z soluble

ZCl most Z soluble (PbCl2, Hg2Cl2, AgCl, AuCl)

ZSO4 most Z soluble (except CaSO4, BaSO4, PbSO4, Hg2SO4, Ag2SO4)

ZCO3, ZPO4, ZSiO4 most Z insoluble(except Na, K, NH4)

ZOH most Z insoluble(except Li, Na, K, NH4)

ZS most Z insoluble(except Na, K, NH4, Mg, Ca)

Hydrophilic compounds have an affinity to water and are usually charged or have polar side groups to their structure that will attract

water. Hydrophobic are water hating compounds that are repelled by water and are

usually neutral (no charge.)?

Hydrophilic compounds have an affinity to water and are usually charged or have polar side groups to their structure that will attract

water. Hydrophobic are water hating compounds that are repelled by water and are

usually neutral (no charge.)?

Tru

e

Fal

se

11%

89%

1. True

2. False

1. True

2. False

Water

Why does ice float?

Ice is less dense than water, therefore it floats.

Solid water molecules form a ordered crystal through hydrogen bonding that spaces the molecules farther apart than when they were in a liquid (less dense).

Why does ice float?

Ice is less dense than water, therefore it floats.

Solid water molecules form a ordered crystal through hydrogen bonding that spaces the molecules farther apart than when they were in a liquid (less dense).

WaterWater

• Density• Densityliquidliquid

iceice

The density of solid water is actually less than it could otherwise be

because hydrogen bonded water is packed slightly less favorably than

could be achieved without hydrogen bonding

vinegar

0 7 14

ammonia

purewater

seawater

GreatSaltLake

acidrain

acid minedrainage

Activity ii i

-sulfide minerals oxidized• produces sulfate, metals, acidity (H+)• pH decreases

– reduced metals released, then oxidized• mainly Fe(II) to Fe(III)• metals precipitate as hydroxides (Fe(OH)3)• hydroxide (OH-) consumed by metals• pH decreases

– pH as low and lower than –3 recorded• {H+} = 103

• [H+] = 103 M???

-sulfide minerals oxidized• produces sulfate, metals, acidity (H+)• pH decreases

– reduced metals released, then oxidized• mainly Fe(II) to Fe(III)• metals precipitate as hydroxides (Fe(OH)3)• hydroxide (OH-) consumed by metals• pH decreases

– pH as low and lower than –3 recorded• {H+} = 103

• [H+] = 103 M???

Iron Mountain, California

vinegar

0 7

purewater

seawater

acidrain

acid minedrainage

-4

-3.6

Iron Mountain, California

Concentration

• Mass per volume – milligram per liter (mg L-1)– microgram per liter (g L-1)– nanogram per liter (ng L-1)

• Moles per volume– moles per liter (M)– logarithmic scale

pH = -log {H+}

• Mass per volume – milligram per liter (mg L-1)– microgram per liter (g L-1)– nanogram per liter (ng L-1)

• Moles per volume– moles per liter (M)– logarithmic scale

pH = -log {H+}

Molarity: M =  moles of solute  or  M = mol                 1 Liter if solution       L Molarity: M =  moles of solute  or  M = mol                 1 Liter if solution       L

Concentration• Mass per mass

– parts per thousand (per mil or %O)– parts per million (ppm)– parts per billion (ppb)– parts per trillion (ppt)

• 1000 milliliters (ml) in a liter (L),

• 1000 millimoles (mM) in a mole

• 1,000,000 micrograms (µg) in a gram.

• Mass per mass– parts per thousand (per mil or %O)– parts per million (ppm)– parts per billion (ppb)– parts per trillion (ppt)

• 1000 milliliters (ml) in a liter (L),

• 1000 millimoles (mM) in a mole

• 1,000,000 micrograms (µg) in a gram.

% to Mg/L% to Mg/LYou can memorize or set up a ratio. Its your choiceYou can memorize or set up a ratio. Its your choice

Rule 1. to convert mg/L (ppm) to % multiply by 0.0001Rule 1. to convert mg/L (ppm) to % multiply by 0.0001

Rule 2. to convert % to mg/L (ppm) multiply by 10,000 Rule 2. to convert % to mg/L (ppm) multiply by 10,000

Rule 3. Ratio for percent to mg/L:Rule 3. Ratio for percent to mg/L:

l

mgx

l

mg%

000,10

%1

Molarity:    M =  moles of solute      or    M = mol                    1 Liter if solution                  L Molarity:    M =  moles of solute      or    M = mol                    1 Liter if solution                  L

% Solutions/Solids% Solutions/SolidsA 1% NaCl solution is made by adding 1 g NaCl (a solid) to enough water to equal a final volume of 100 ml.

A 1 % ethanol solution is made by adding 1 ml ethanol (a liquid) to enough water to equal a final volume of 100 ml

To figure out how much of a solid you need to make up a percent solution

(mass/volume) * (volume).

EX: How do you make up 1 L of a 15% glucose solution?

(15g glucose/100 ml) * 1000 ml = 150 g glucose.

You would measure out 150 g glucose and then add enough water to have a final volume of 1000 ml.

A 1% NaCl solution is made by adding 1 g NaCl (a solid) to enough water to equal a final volume of 100 ml.

A 1 % ethanol solution is made by adding 1 ml ethanol (a liquid) to enough water to equal a final volume of 100 ml

To figure out how much of a solid you need to make up a percent solution

(mass/volume) * (volume).

EX: How do you make up 1 L of a 15% glucose solution?

(15g glucose/100 ml) * 1000 ml = 150 g glucose.

You would measure out 150 g glucose and then add enough water to have a final volume of 1000 ml.

% Solutions/Liquid% Solutions/LiquidTo figure out how much of a liquid you need to make up a percent solution

(volume material/volume solution) * (total final volume).

For example: How do you make up 0.3 L of a 15% ethanol solution?

(15ml ethanol/100 ml) * 300 ml = 45 ml ethanol.

You would measure out 45 ml of ethanol and then add water to a final volume of 300 ml.

To figure out how much of a liquid you need to make up a percent solution

(volume material/volume solution) * (total final volume).

For example: How do you make up 0.3 L of a 15% ethanol solution?

(15ml ethanol/100 ml) * 300 ml = 45 ml ethanol.

You would measure out 45 ml of ethanol and then add water to a final volume of 300 ml.

Molar SolutionsMolar SolutionsWhen making up molar solutions from pure starting materials, you need to know the weight of a mole of the material, and the desired final volume.

For example, the following are some molar weights:Material Weight of 1 moleNaCl 58.5 gglucose 180 gCaCl2 111 gNaOH 40 g

To figure out what mass of material you need to make up a solution:

(g/mole) * (mole/L) * L

When making up molar solutions from pure starting materials, you need to know the weight of a mole of the material, and the desired final volume.

For example, the following are some molar weights:Material Weight of 1 moleNaCl 58.5 gglucose 180 gCaCl2 111 gNaOH 40 g

To figure out what mass of material you need to make up a solution:

(g/mole) * (mole/L) * L

Molar SolutionsMolar Solutions (g/mole) * (mole/L) * LExamples: To make 1 L of 1 M NaCl, you need:(58.5 g NaCl/mole) * (1 M / L) * 1 L = 58.5 g NaCl.

To prepare the solution, measure 58.5 g of NaCl and add enough water so the final volume is equal to 1 L.

To make 300 ml of 10 mM CaCl2, you need(111 g CaCl2/mole) * (0.01 mole/L) * 0.3 L = .333 g CaCl2.

To prepare the solution, measure out 0.333 g CaCl2, and enough water so that the final volume is 300 ml.

(g/mole) * (mole/L) * LExamples: To make 1 L of 1 M NaCl, you need:(58.5 g NaCl/mole) * (1 M / L) * 1 L = 58.5 g NaCl.

To prepare the solution, measure 58.5 g of NaCl and add enough water so the final volume is equal to 1 L.

To make 300 ml of 10 mM CaCl2, you need(111 g CaCl2/mole) * (0.01 mole/L) * 0.3 L = .333 g CaCl2.

To prepare the solution, measure out 0.333 g CaCl2, and enough water so that the final volume is 300 ml.

DilutionsDilutionsThe relationship between starting concentration, final concentration, and dilution is:

Ci * D = Cf where Ci = initial concentration, Cf = final concentration, and D = dilution.

For example: How do you dilute a 1000 mM stock of glucose to give you a final concentration of 10 mM?

D = Cf/Ci = 10 mM / 1000 mM = 1/100.

You need to dilute the concentrated stock 1/100, so you could mix 1 ml of your stock with 99 ml of water. Another example: How do you dilute 70% ethanol to obtain 15% ethanol? D = Cf/Ci = 15%/70% = 15/70 You could take 15 ml of your stock and add 55 ml of water.

The relationship between starting concentration, final concentration, and dilution is:

Ci * D = Cf where Ci = initial concentration, Cf = final concentration, and D = dilution.

For example: How do you dilute a 1000 mM stock of glucose to give you a final concentration of 10 mM?

D = Cf/Ci = 10 mM / 1000 mM = 1/100.

You need to dilute the concentrated stock 1/100, so you could mix 1 ml of your stock with 99 ml of water. Another example: How do you dilute 70% ethanol to obtain 15% ethanol? D = Cf/Ci = 15%/70% = 15/70 You could take 15 ml of your stock and add 55 ml of water.

M1V1=M2V2M1V1=M2V2

M1V1 = M2V2 and solve for any quantity we wish to.

1 is starting (concentrated) and 2 is ending (dilute)

For example suppose we want to make 100 ml of a .10 M solution from a stock solution of 6M strength

Using the M1V1 = M2V2 equation

M1V1 = M2V2

(100)(.10)  =   (x) (6) or 6x = 10, x = 1.67ml

This means if we place 1.67 ml of the concentrated solution into a graduated cylinder and add enough water to form 100 ml we have the correct strength solution.

M1V1 = M2V2 and solve for any quantity we wish to.

1 is starting (concentrated) and 2 is ending (dilute)

For example suppose we want to make 100 ml of a .10 M solution from a stock solution of 6M strength

Using the M1V1 = M2V2 equation

M1V1 = M2V2

(100)(.10)  =   (x) (6) or 6x = 10, x = 1.67ml

This means if we place 1.67 ml of the concentrated solution into a graduated cylinder and add enough water to form 100 ml we have the correct strength solution.

Nightly Competition

The objectives for this week to become familiar with the fundamentals of water and its unique chemical properties have

been met.

The objectives for this week to become familiar with the fundamentals of water and its unique chemical properties have

been met.

Stro

ngly A

gree

Agre

e

Dis

agre

e

Stro

ngly D

isag

ree

83%

0%0%

17%

1. Strongly Agree

2. Agree

3. Disagree

4. Strongly Disagree

1. Strongly Agree

2. Agree

3. Disagree

4. Strongly Disagree