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Topic 5: Matter & Energy
Regents Chemistry Mr. Mancuso
Matter
Anything that has _______________________ and _____________________________________
o ________________________________________________________________________
States of Matter
(1) Gas / Vapor
o ________________________________________________________________________
o ________________________________________________________________________
o ________________________________________________________________________
o _______________________________________________________________________ _______________________________________________________________________ ________________________________________________________________________
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(2) Liquid
o ________________________________________________________________________
o ________________________________________________________________________
o ________________________________________________________________________
o ________________________________________________________________________
(3) Solid
o ________________________________________________________________________
o ________________________________________________________________________
o ________________________________________________________________________
(4) Plasma
o Highly charged, gas‐like phase (fire)
~3~
Arrangement of Matter
(1) Elements
o ________________________________________________________________________ ________________________________________________________________________
o ________________________________________________________________________
(2) Compounds
o ________________________________________________________________________ ________________________________________________________________________
o ________________________________________________________________________
(3) Mixtures
o ________________________________________________________________________ ________________________________________________________________________
Mixtures are going to be one of the following consistencies:
(a) Homogeneous: ________________________________________________________ _________________________________________________________________
(b) Heterogeneous: _______________________________________________________ _________________________________________________________________
~4~
Practice An element consists if only one kind of atom. A compound consists of two or more different elements chemically combined in a fixed ratio. The components of a mixture can be any proportion and are not chemically bound. Classify each of the following as an element, compound, or mixture by writing E, C, or M in the space provided.
1. sodium _____ 2. water _____ 3. soil _____ 4. coffee _____ 5. oxygen _____ 6. alcohol _____ 7. carbon dioxide _____ 8. cake batter _____ 9. air _____ 10. soap _____ 11. iron _____ 12. salt water _____ 13. ice cream _____ 14. nitrogen _____ 15. eggs _____ 16. blood _____ 17. gold _____ 18. table salt _____ 19. milk _____ 20. cola _____ 21. orange juice _____ 22. helium _____ 23. methane gas _____ 24. nail polish _____
~5~
Composition of Mixtures:
(a) Element / Element: ___________________________________________________________
(b) Compound / Compound: ______________________________________________________
(c) Element / Compound: _________________________________________________________
ELEMENTS COMPOUND (AB)
A B
HETEROGENEOUS MIXTURE (A & B) HETEROGENEOUS MIXTURE (A & AB)
Mixtures can be separated by ______________________________________________________
ACTIVITY: POGIL – Classification of Matter
~6~
Practice Identify each as a substance or a mixture. If it is a substance, identify it as an element or a compound. If it is a mixture, identify it as a mixture of compounds, elements, or both.
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Separation of Mixtures Heterogeneous mixtures can be separated by using the following techniques:
(1) _____________________________________________________________________
(2) _____________________________________________________________________
(3) _____________________________________________________________________ Homogeneous mixtures (aqueous solutions) can be separated by using the following techniques:
(1) ____________________________________
o ________________________________________________________________
(2) ____________________________________
o ________________________________________________________________
(3) ____________________________________
o _________________________________________________________________
~8~
Practice All matter can be classified as either a substance (element or compound) or a mixture (heterogeneous or homogeneous).
Matter
Substance Mixtures can write chemical variable ratio formula
Element : Compound: Homogeneous Heterogeneous one type two or more different solutions colloids and of atom atoms chemically suspensions bonded
Classify each of the following as to whether it is a substance or a mixture. If it is a substance, write Element or Compound in the substance column. If it is a mixture, write Heterogeneous or Homogeneous in the mixture column.
Type of Matter Substance Mixture
1. chlorine
2. water
3. soil
4. sugar water
5. oxygen
6. carbon dioxide
7. rocky road ice cream
8. alcohol
9. pure air
10. iron
~9~
Properties of Matter
(1) Physical Properties
o Can be measured or observed without changing the substance into different substance
Examples:
(2) Chemical Properties
o Characteristics that describe how the substance reacts (or doesn’t react) with other
substances
Guided Practice
(1) One mole of water weighs 18.0 grams ____________
(2) Water expands when it freezes ____________
(3) Pure water has a pH of 7.0 ____________
(4) Water reacts with sodium bicarbonate to form CO2 ____________
(5) Water does not rust gold ____________
~10~
Measurable Properties of Matter
(1) Extensive Properties
o Properties that depend on how much of a particular sample is on hand Examples:
(2) Intensive Properties
o Properties that do not depend on how much of a sample is on hand
Examples:
Guided Practice
(1) One mole of water weighs 18.0 grams ____________
(2) There are 300 mL of water in a 500 mL beaker ____________
(3) Pure water has a pH of 7.0 ____________
(4) Water reacts with sodium bicarbonate to form CO2 ____________
(5) My sample of water weighs 10.0 grams ____________
~11~
Practice: A physical property is observed with the senses and can be determined without destroying the object. For example, color, shape, mass, length, and odor are all examples of physical properties. A chemical property indicates how a substance reacts with something else. The original substance is fundamentally changed in observing a chemical property. For example, the ability of iron to rust is a chemical property. The iron has reacted with oxygen, and the original iron metal has changed. Now it exists as iron oxide, a different substance. Classify the following properties as either chemical or physical by putting a check in the appropriate column.
Physical Property Chemical Property 1. blue color
2. density
3. flammability
4. solubility
5. reacts with acid to form hydrogen gas
6. supports combustion
7. sour taste
8. melting point
9. reacts with water to form a gas
10. reacts with a base to form water
11. hardness
12. boiling point
13. can neutralize a base
14. luster
15. odor
~12~
Changes in Matter
(1) Physical Change
o When a physical property of a substance is changed, without changing it into a new substance
Examples:
(2) Chemical Change
o Any change that results in the production of new substances
Examples:
Law of conservation of matter: ____________________________________________________________________________ ____________________________________________________________________________
~13~
Practice: In a physical change, the original substance still exists, it has only changed in form. In a chemical change, a new substance is produced. Energy changes always accompany chemical changes.
Classify the following as being a physical or chemical change. 1. sodium chloride dissolves in water ________________________ 2. hydrochloric acid reacts with potassium hydroxide to produce a salt, water, and heat. ________________________ 3. a pellet of sodium is sliced in two ________________________ 4. water is heated and changed to steam ________________________ 5. potassium chlorate decomposes to potassium chloride and oxygen gas. ________________________ 6. iron rusts ________________________ 7. when placed in water, a sodium pellet catches on fire as hydrogen gas is liberated and sodium
hydroxide forms ________________________ 8. evaporation ________________________ 9. ice melting ________________________ 10. milk sours ________________________ 11. sugar dissolves in water ________________________ 12. pancakes cooking on the griddle ________________________ 13. grass growing in lawn ________________________ 14. a tire is inflated with air ________________________ 15. food is digested in the stomach ________________________ 16. water is absorbed by a paper towel ________________________
~14~
Review
1. Which of the following cannot be decomposed by chemical means?
(1) Sodium (2) ethanol (3) sucrose (4) water
2. A compound differs from an element in that a compound (1) Is homogenous (2) Has definite composition (3) Has a definite melting point (4) Can be decomposed by a chemical reaction
3. A compound differs from a mixture in that a compound always has a (1) Homogenous composition (2) Maximum of two elements (3) Minimum of three elements (4) Heterogeneous composition
4. Most elements are (1) Metals (2) nonmetals (3) gases (4) made in the lab
5. Which of these materials is a mixture? (1) Water (2) air (3) methane (4) magnesium
6. Which statement is an identifying characteristic of a mixture (1) A mixture can consist of a single element (2) A mixture can be separated by physical means (3) A mixture must have a definite composition by weight (4) A mixture must be homogeneous
7. Which substance can be decomposed by a chemical change? (1) Ammonia (2) aluminum (3) magnesium (4) manganese
8. A sample of a material is passed through filter paper. A white deposit remains on the paper, and a clear liquid passes through. The clear liquid is then evaporated, leaving a white residue. What can you determine about the nature of the sample? _____________________________________________________________________________ _____________________________________________________________________________
~15~
9. What are some of the differences between a mixture of iron and oxygen, and a compound composed of iron and oxygen? ____________________________________________________________________________ ____________________________________________________________________________
10. Examine the contents of the four containers shown below. Identify each as containing: only elements; only compounds; or a mixture of these. Explain each of your answers.
A: __________________________________________________________________ B: __________________________________________________________________ C: __________________________________________________________________ D: __________________________________________________________________
Are the contents in container D homogeneous or heterogeneous? Explain: _______________________________________________________________________ _______________________________________________________________________
~16~
Energy
Heating and Cooling Curves (Phase Diagrams)
HEATING CURVE
This figures shows the ____________________________________________________________
___________________________________________________________
Heat energy _____________________________________________________________ _____________________________________________________________ _____________________________________________________________
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______ AB : ________________________________________________________________ ________________________________________________________________ B : ________________________________________________________________ ______ BC : ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ______ CD : ________________________________________________________________ ________________________________________________________________ D : ________________________________________________________________ ______ DE : ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ______ EF : ________________________________________________________________ _______________________________________________________________
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COOLING CURVE
This figures shows the ____________________________________________________________
___________________________________________________________
Sublimation: ___________________________________________________________________ ___________________________________________________________________ Deposition: ____________________________________________________________________ ____________________________________________________________________
~19~
Review
1. Which substance has a definite shape and a definite volume at STP?
(1) NaCl (aq) (2) Cl2 (g) (3) CCl4 (l) (4) AlCl3 (s)
2. Which sample is most likely to take the shape of and occupy the total volume of the container? (1) CO2 (g) (2) CO2 (l) (3) CO2 (aq) (4) CO2 (s)
3. As a substance changes from a liquid to a gas, the average distance between molecules (1) Decrease (2) increase (3) remains the same
4. In which phase are the particles the most random? (1) Solid (2) liquid (3) gas
5. Which phase change represents sublimation?
(1) NH3 (l) NH3 (g)
(2) CO2 (s) CO2 (g)
(3) KI (s) KI (l)
(4) H2O (l) H2O (s)
6. As ice cools from 273 K to 263 K, the average kinetic energy of its molecules (1) Decreases (2) increases (3) remains the same
7. A solid substance initially at a temperature below its melting point is heated at a constant rate. The heating curve is shown below:
Which portions of the graph represent times when heat is absorbed and potential energy increases while kinetic energy remains constant? (1) A and B (2) B and D (3) A and C (4) C and D
~20~
8. A gaseous substance initially at a temperature above its boiling point is cooled at a constant rate. The cooling curve is shown below:
How much time passes between the first appearance of the liquid phase of the substance and the presence of the substance completely in the solid phase? (1) 5 minutes (2) 2 minutes (3) 7 minutes (4) 4 minutes
9. Which change of phase is endothermic?
(1) Gas solid
(2) Gas liquid
(3) Liquid solid
(4) Liquid gas
10. By using a paper filter, which of the following can be separated? (1) Two immiscible liquids (2) Two heterogeneous liquids (3) A solid and a liquid (4) Two miscible liquids
11. Distillation can be used to separate (1) Two solids (2) Two miscible liquids with different boiling points (3) Solids suspended in a gas (4) Gases with different densities
12. The principle that allows paper chromatography to separate mixtures depends on the different components having (1) Different boiling points (2) Different attractions to the paper (3) Different densities (4) Similar solubility in water
~21~
Temperature and Its Measurement Temperature (which measures the average kinetic energy of the molecules) can be measured using three common scales: Celsius, Kelvin, and Fahrenheit. We use the following formulas to convert from one scale to another. Celsius is the scale most desirable in laboratory work. Kelvin represents the absolute scale. Fahrenheit is the old English scale which is never used in the lab
Celsius to Kelvin Kelvin to Celsius Celsius to Fahrenheit Fahrenheit to Celsius K = °C + 273 °C = K ‐ 273 °F = 9/5 °C + 32 °C = 5/9 (°F ‐ 32)
Complete the following chart. All measurements are good to 1° C or better.
°C K °F
1
0 °C
2
212 °F
3
450 K
4
98.6 °F
5
‐ 273 °C
6
294 K
7
77 °F
8
225 K
9
‐ 40 °C
~22~
Measurement of Heat
Temperature is a number that is related to the average kinetic energy of the molecules of a substance. If temperature is measured in Kelvin degrees, then this number is directly proportional to the average kinetic energy of the molecules.
Heat is a measurement of the total energy in a substance. That total energy is made up of not only of the kinetic energies of the molecules of the substance, but total energy is also made up of the potential energies of the molecules.
Temperature and Heat are NOT the same thing!
ACTIVITY: POGIL – Calorimetry
Δ Heat when there is no phase change:
The amount of heat given off or absorbed when there is no change of phase can be calculated using the following equation:
ΔH during a phase change:
Depending on the change of phase, use one of the following formulas to calculate the change in heat:
~23~
Guided Practice
(1) How much heat (in joules) is absorbed when 50.0 g of water is heated from 30.2°C to 58.6°C?
(2) Identify the change in heat when 82.30 grams of water is cooled from 63.2°C to 32.0°C.
~24~
(3) How many joules are required to melt 255 g of ice at 0°C?
(4) How many kilojoules of energy are required to evaporate 88.0 g of water?
(5) Identify the change in heat when 150.0 grams of aluminum is heated from 300.0 K to 387.2 K (specific heat of aluminum = 0.90 J/g•°C)
(6) Identify the final temperature of 47.3 grams of water, that started at 25.0°C, after 3550 J of heat energy is added.
~25~
(7) What is the energy change, in kilojoules , when 3.0 x 104 g of water freezes?
(8) How many joules are required to vaporize 423 g of water at 100°C and 1 atm of pressure?
(9) What is the mass of water that is changed from 50.0°C to 70°C when 2500 J of heat energy is
added?
~26~
Practice: Heat (or energy) can be measured in units of joules. When there is a change in temperature (∆T), heat (Q) can be calculated using these formulas:
q = mC∆T q = mHf q = mHv
q = heat ∆T = change in temperature m = mass Hf = heat of fusion C = specific heat capacity Hv = heat of vaporization
Solve the following problems. Show your work. Use significant figures.
1. How many joules of heat are given off when 5.0 g of water cool from 75.0°C to 25.0°C?
____________
2. How many joules does it take to melt 35 g of ice at 0°C? ____________
3. How many kilojoules are needed in Problem 2? ____________
4. How many grams of water will condense when 1.9 x 105 J of energy is released ? ____________
5. How many joules of heat are necessary to raise the temperature of 25 g of water from 10.0°C to 60.0°C?
____________
6. How many grams of water melts when 2 x 104 J of heat energy is absorbed? ____________
~27~
7. Determine the amount of heat absorbed or released in each of the following changes.
(a) 40.0 g of water heated from 10.0°C to 30.0°C. ____________
(b) 25.0 g of water cooled from 85.0°C to 40.0°C. ____________
(c) 65.5 g of water heated from 32.5°C to 48.7°C. ____________
(d) 135.6 g of water cooled from 95.8°C to 21.6°C ____________
(e) 100.0 g of ice melted, with no temperature change ____________
(f) 40.0 g of water, boiled at 100.0 °C ____________
(g) 284.2 g of water heated from 120 K to 145 K ____________
(h) 643.2 g of water heated from 284 K to 323 K ___________
(i) 14.78 g of water freezes with no temperature change ___________
(j) 3.66 g of water evaporates ___________
(k) 584.3 g of water boils ___________
(l) 0.732 g of water melts ___________
(m) 0.450 g of water is heated from 700 K to 933 K ___________
(n) 92.0 g of water is heated from 263 K to 268 K ___________
~28~
Use the following chart to answer questions 8 – 11
Specific heat at 25°C:
Al = 0.90 J/g ‐ K Fe = 0.45 J/g ‐ K Pb = 0.16 J/g ‐ K Mg = 1.02 J/g ‐ K
8. 30.0 g of aluminum heated from 15.0°C to 35.0°C ____________
9. 450.0 g of iron cooled from 125.0°C to 45.0°C ____________
10. 62.3 g of lead heated from 21.7°C to 136.4°C ____________
11. 195.4 g of magnesium cooled from 120.6°C to 14.9°C ____________
~29~
Practice
Answer the following questions using the chart above. 1. What is the freezing point of the substance? _________ 2. What is the boiling point of the substance? _________ 3. What is the melting point of the substance? _________ 4. What letter represents the range where the solid is being warmed? _________ 5. What letter represents the range where the liquid is being warmed? _________ 6. What letter represents the range where the vapor is being warmed? _________ 7. What letter represents the melting of the solid? _________ 8. What letter represents the vaporization of the liquid? _________ 9. What letter(s) show a change in potential energy? _________ 10. What letter(s) show a change in kinetic energy? _________ 11. What letter represents condensation? _________ 12. What letter represents solidification? _________
~30~
Review
1. Which is not a form of energy? (1) Light (2) temperature (3) electricity (4) heat
2. The minimum number of fixed reference points required to establish the Celsius temperature scale for a thermometer is: (1) 1 (2) 2 (3) 3 (4) 4
3. When the temperature of an object changes by 100°C, the same temperature change in Kelvins would be: (1) 100 K (2) 173 K (3) 273 K (4) 373 K
4. How many joules of heat energy are released when 50.0 g of water are cooled from 70°C to 60°C? (1) 41.8 J (2) 2.09 x 103 J (3) 209 J (4) 4.18 x 103 J
5. When 20.0 g of a substance is completely melted at its melting point, 3444 J are absorbed. What is the heat of fusion for this substance? (1) 41 J/g (2) 172 J/g (3) 16,400 J/g (4) 68,900 J/g
6. If 100.0 J are added to 20.0 g of water at 30.0°C, what will be the final temperature of the water?
_______________________
7. The normal boiling point of water is equal to: (1) 173 K (2) 273 K (3) 373 K (4) 473 K
8. If 4 grams of water at 1°C absorbs 33.6 J of heat, the temperature of the water will change by: (1) 1°C (2) 2°C (3) 3°C (4) 4°C
~31~
9. The amount of energy needed to convert a unit mass of ice to liquid at constant temperature is called its heat of:
(1) evaporation (2) reaction (3) fusion (4) vaporization 10. What term represents the change of a substance from the gas phase to the liquid phase? (1) condensation (2) vaporization (3) evaporation (4) fusion 11. How many joules of heat energy are absorbed when 100 grams of water is heated from 20°C to
30°C? (1) 4200 J (2) 42,000 J (3) 420,000 J (4) 420 J 12. A closed system is shown in the diagram below:
The rate of vapor formation at equilibrium is:
(1) less than the rate of liquid formation (2) greater than the rate of liquid formation (3) equal to the rate of liquid formation
13. Which change results in the release of energy? (1) the melting of H2O (s) (2) the boiling of H2O (l) (3) the evaporation of H2O (l) (4) the condensation of H2O (g) 14. The strongest intermolecular forces of attraction exist in a liquid whose heat of vaporization is: (1) 100 J/gram (2) 200 J/gram (3) 300 J/gram (4) 400 J/gram 15. Under the same conditions of temperature and pressure, a liquid differs from a gas because the
particles of the liquid (1) are in constant straight‐line motion (2) take the shape of the container they occupy (3) have no regular arrangement (4) have stronger intermolecular forces of attraction between them
~32~
16. If two systems at different temperatures have contact with each other, heal will flow from the system at: (1) 20°C to a system at 303 K (3) 40°C to a system at 293 K (2) 30°C to a system at 313 K (4) 50°C to a system at 333 K
17. At which point do a liquid and a solid of the same substance exist together in equilibrium?
(1) sublimation point (3) boiling point (2) vaporization point (4) melting point
18. The graph below represents the relationship between temperature and time as heat is added
uniformly to a substance, starting when the substance is solid below its melting point.
Which portions of the graph represent times when heat is absorbed and potential energy increases while kinetic energy remains constant?
(1) A and B (2) B and D (3) A and C (4) C and D
19. When steam condenses to water, the surrounding temperature (1) increases (2) decreases (3) remains the same