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States of Matter
and Introduction to
Thermochemistry

I. States of Matter
A. Solid
1. Properties

a. has distinct volume and well-defined shape (does not take shape of its container)
b. particles tend to vibrate about fixed points
c. particles are packed against one another in a rigid and organized arrangement

2. Phase changes of solids
a. Melting; Freezing

                            melting
              Solid ----------------> Liquid
                      <---------------

                           freezing 

_________________ - temperature at which a solid turns into a liquid
_________________ - temperature at which a liquid turns into a solid

The ___________________ and __________________ are the ____________temperature.

_____________________ have ___________ melting points (ex. melting point of NaCl = 801 oC)
_____________________ have ___________ melting points (ex. melting point of hydrogen chloride = -112 oC)

b. Sublimation; Deposition

______________________ - the change of a substance from a solid to a vapor or without passing through the liquid state
______________________ - the change of a substance from a vapor to a solid without passing through the liquid state

                       sublimation
           Solid ------------------> Gas
                    <-----------------

                       deposition
 

Examples of solid that sublimate: _______________________, _______________ (_______________________), __________________
 

B. Liquid
1. Properties

a. occupies fixed volume, but has no shape of its own
b. particles are relatively free to move and slide past one another
c. particles vibrate and spin as they move from place to place

2. Phase Changes of Liquids
a. Freezing; Melting
b. Vaporization; Condensation

                                    vaporization or evaporation
                  Liquid --------------------------------------> Vapor (Gas)
                            <--------------------------------------

                                              condensation
 

_______________________ - conversion of a liquid to a gas or vapor
__________ - matter that has no definite shape or volume; it is the normal state of the substance at room temperature (ex. oxygen, nitrogen, argon)
____________ - gaseous state of a substance that is normally a liquid or solid at room temperature (ex. water vapor)
__________________ - conversion of a liquid to a gas or vapor occurs at surface of the liquid that is not boiling
__________________ - temperature at which the vapor pressure of a liquid just equals the external pressure
__________________ - boiling point of a liquid at a pressure of 1 atm

C. Gas
1. Properties

a. takes shape and volume of its container
b. particles of a gas move rapidly in constant random motion
c. particles move independent of each other (there is no attractive or repulsive force between the particle)

2. Phase Changes of Gases
a. Condensation; Vaporization (Evaporation)

                                            Condensation
      Vapor (Gas) ------------------------------------------> Liquid
                          <------------------------------------------

                                 Vaporization or Condensation

b. Sublimation; Deposition

                                              Deposition
                               Gas --------------------> Solid
                                      <-------------------

                                              Sublimation

D. Plasma - the fourth state of matter?

Plasma occurs at extremely high temperatures (millions of degrees C). At these temperatures, all electrons have been removed from the atom. The resulting fluid of bare nuclei and free electrons is called ____________________.

E. Phase Diagrams

1. ____________________ - gives the conditions of temperature and pressure at which a substance exists as solid, liquid, and gas (vapor)
2. Every substance has its own characteristic phase diagram
3. ____________________ - the temperature and pressure under which all three phases of a substance may exist in equilibrium with one another



III. What is THERMOCHEMISTRY and how does it relate to physical and chemical changes?

A. Introduction to Thermochemistry
1. Definitions of Energy, Work, Heat, Temperature

a. ______________ - the ability (or capacity) of a system to do work or supply (or produce) heat
b. _________________
simple definition - _______________________________________________
more complex definition - _________________________________________
                                       __________________________________________

c. ________ - transfer of energy between two objects due to temperature differences
d. ______________________ - property which determines the direction heat will flow when two objects are brought into contact

2. Thermochemistry
a. Types of processes

_____________________ - process that absorbs heat from the surroundings (q > 0)
_____________________ - process that releases heat to its surroundings (q < 0)
b. Equation that expresses heat changes:

Heat = q =

q =
______________________ (expressed in calories or Joules)

note: 1000 calories = 1 kilocalorie = 1 Calorie
4.184 J = 1 calorie
m = ____________________________ (in grams)
T = ____________________________ (in oC)
C = ___________________________(cal/g oC or J/g oC)
_______________________- the amount of heat it takes to raise the temperature of 1 g of a substance 1 oC

c. Specific heats of some common substances
from Table 11.2, p. 296

 



d. Thermochemistry problems

Problem #1: How much energy must be absorbed by 20.0 g of water to increase its temperature from 25.0 oC to 100.0 oC?





Problem #2: How much energy must be absorbed by 20.0 g of iron to increase its temperature from 25.0 oC to 100.0 oC?






Problem #3: When 15.0 g of steam drops in temperature from 275.0 oC to 250.0 oC?





d. Questions

1) On hot summer days, why is the air cooler near large bodies of water such as lakes?





2) A puddle of water and a manhole cover sit out on a hot sunny day. Which is hotter? Why?






3) Explain the following statement by Mark Twain: “The coldest winter I ever spent was the summer I spent in San Francisco.”
 

B. How to measure heat changes: Calorimetry

_______________________ - way to measure heat change for a chemical or physical process


C. Heat Changes in Phase Changes
1. Heat of Fusion and Solidification

______________________________ (    ^   Hfus) - heat absorbed by one mole of a substance in melting from a solid to a liquid at a constant temperature

______________________________ (   ^    Hsolid) - heat lost when one mole of a liquid solidifies at a constant temperature

                     ^   Hfus =    ^  Hsolid

Example: water

                     H2O (s) ---> H2O (l)                  ^  Hfus = 6.01 kJ/mol

                     H2O (l) ---> H2O (s)                  ^  Hsolid = - 6.01 kJ/mol

Molar Heat of Fusion Equation: q =  ^ Hfus  x  moles

                                                      q =  ^ Hfus   x   mass   x          1         
                                                                                                molar mass

Problem #1: 3.14 grams of water is being melted at its melting point of
0 oC.  How much energy (in kJ) is required?





Problem #2: 53.1 grams of water exists as a liquid at 0 oC. How much
energy must be removed to turn the water into a solid at 0 oC?

 



Questions:

1) At what temperature does water freeze?

2) At what temperature does ice melt?

3) In freezing weather, how does spraying fruit and flooding orchards with a few inches of water keep the fruit from freezing?





2. Heat of Vaporization and Condensation

________________________________ ( ^ Hvapor) - the amount of heat necessary to vaporize (boil) one mole of a liquid

________________________________ ( ^ Hcond ) - the amount of heat released when one mole of a vapor condenses

                                       ^ Hvapor = - ^ Hcond

Example: water

                                     H2O (l) ---> H2O (g)                     ^ Hvapor = 40.7 kJ/mol

                                     H2O (g) ---> H2O (l)                     ^ Hcond = - 40.7 kJ/mol


       Molar Heat of Vaporization Equation:
                                                                           q = ^ Hvapor  x  moles

                                                                           q = ^ Hvapor  x  mass x           1         
                                                                                                                  molar mass


Problem #1: 49.5 g of water is being boiled at its boiling point of 100 oC. How many kJ is required?

 



Problem #2:    80.1 g of water exists as a gas at 100 oC.    How many kJ must be removed to turn the water into liquid at 100 oC?





More Practice:

Problem #3: How many grams of ice at 0 oC could be melted by the addition of 2.25 kJ of heat?








Problem #4: How many kilojoules of heat are required to melt a 10.0 g popsicle at 0 oC? Assume the popsicle has the same molar mass and heat capacity as water.








Problem #5: How much heat (in kJ) is absorbed when 63.7 g of liquid water at 100 oC is converted to steam at 100 oC?








D. Time-Temperature Graph

Problem: Heat a container that has 72.0 grams of ice from -10.0 oC to 120.0 oC.

Five major steps are required to solve this problem:

1) the ice rises in temperature from -10.0 oC to 0.0 oC
2) the ice melts at 0.0 oC
3) the liquid water then rises in temperature from zero to 100.0 oC
4) the liquid water then boils at 100.0 oC
5) the steam then rises in temperature from 100.0 oC to 120.0 oC

Each step requires a calculation.
 


HOMEPAGE  
   






















II. What is THERMOCHEMISTRY and how does it relate to physical and chemical changes?

A. Introduction to Thermochemistry 
1. Definitions of Energy, Work, Heat, Temperature
a. ______________ - the ability (or capacity) of a system to do work or supply (or produce) heat
b. _________________
simple definition - _______________________________________________
more complex definition - _________________________________________
_________________________________________ c. ________ - transfer of energy between two objects due to temperature differences
d. ______________________ - property which determines the direction heat will flow when two objects are brought into contact

2. Thermochemistry
a. Types of processes
_____________________ - process that absorbs heat from the surroundings (q > 0)
_____________________ - process that releases heat to its surroundings (q < 0)
b. Equation that expresses heat changes:

Heat = q = 

q = ______________________ (expressed in calories or Joules)

note: 1000 calories = 1 kilocalorie = 1 Calorie
4.184 J = 1 calorie
m = ____________________________ (in grams)
T = ____________________________ (in oC)
C = ___________________________(cal/g oC or J/g oC)
_______________________- the amount of heat it takes to raise the temperature of 1 g of a substance 1 oC

c. Specific heats of some common substances
from Table 11.2, p. 296







d. Thermochemistry problems

Problem #1: How much energy must be absorbed by 20.0 g of water to increase its temperature from 25.0 oC to 100.0 oC?





Problem #2: How much energy must be absorbed by 20.0 g of iron to increase its temperature from 25.0 oC to 100.0 oC?






Problem #3: When 15.0 g of steam drops in temperature from 275.0 oC to 250.0 oC?





d. Questions

1) On hot summer days, why is the air cooler near large bodies of water such as lakes?





2) A puddle of water and a manhole cover sit out on a hot sunny day. Which is hotter? Why?






3) Explain the following statement by Mark Twain: “The coldest winter I ever spent was the summer I spent in San Francisco.”
B. How to measure heat changes: Calorimetry

_______________________ - way to measure heat change for a chemical or physical process


C. Heat Changes in Phase Changes
1. Heat of Fusion and Solidification

______________________________ ( Hfus) - heat absorbed by one mole of a substance in melting from a solid to a liquid at a constant temperature

______________________________ ( Hsolid) - heat lost when one mole of a liquid solidifies at a constant temperature

Hfus = Hsolid

Example: water

H2O (s) ---> H2O (l) Hfus = 6.01 kJ/mol

H2O (l) ---> H2O (s) Hsolid = - 6.01 kJ/mol

Molar Heat of Fusion Equation: q = Hfus x moles

q = Hfus x mass x 1 
molar mass

Problem #1: 3.14 grams of water is being melted at its melting point of 
0 oC. How much energy (in kJ) is required?





Problem #2: 53.1 grams of water exists as a liquid at 0 oC. How much 
energy must be removed to turn the water into a solid at 0 oC? 



Questions:

1) At what temperature does water freeze?

2) At what temperature does ice melt?

3) In freezing weather, how does spraying fruit and flooding orchards with a few inches of water keep the fruit from freezing?





2. Heat of Vaporization and Condensation

________________________________ ( Hvapor) - the amount of heat necessary to vaporize (boil) one mole of a liquid

________________________________ ( Hcond ) - the amount of heat released when one mole of a vapor condenses

Hvapor = - Hcond

Example: water

H2O (l) ---> H2O (g) Hvapor = 40.7 kJ/mol

H2O (g) ---> H2O (l) Hcond = - 40.7 kJ/mol


Molar Heat of Vaporization Equation: 
q = Hvapor x moles

q = Hvapor x mass x 1 
molar mass

Problem #1: 49.5 g of water is being boiled at its boiling point of 100 oC. How many kJ is required?



Problem #2: 80.1 g of water exists as a gas at 100 oC. How many kJ must be removed to turn the water into liquid at 100 oC?







More Practice:

Problem #3: How many grams of ice at 0 oC could be melted by the addition of 2.25 kJ of heat?








Problem #4: How many kilojoules of heat are required to melt a 10.0 g popsicle at 0 oC? Assume the popsicle has the same molar mass and heat capacity as water.








Problem #5: How much heat (in kJ) is absorbed when 63.7 g of liquid water at 100 oC is converted to steam at 100 oC?








D. Time-Temperature Graph

Problem: Heat a container that has 72.0 grams of ice from -10.0 oC to 120.0 oC. 

Five major steps are required to solve this problem:

1) the ice rises in temperature from -10.0 oC to 0.0 oC
2) the ice melts at 0.0 oC
3) the liquid water then rises in temperature from zero to 100.0 oC
4) the liquid water then boils at 100.0 oC
5) the steam then rises in temperature from 100.0 oC to 120.0 oC

Each step requires a calculation.