1. Chapter 2 Energy and Matter

2. 2-1 Energy Energy – is the capacity to do work. Forms of Energy
Work – is the ability to move an object over a distance against a resisting force.
Forms of Energy
Light
Mechanical
Chemical
Heat
Electrical

3. 2-1 Energy Classifications of Energy Radiant Energy Potential Energy
Energy in which little matter is needed.
Potential Energy
Stored energy
Kinetic Energy
Energy of motion

4. 2-1 Energy Measuring Energy Units of energy
Joules (J) – S.I. Unit of energy.
calorie (cal) – amount of heat needed to raise the temperature of 1 g of water by 1oC.
Calorie(Cal) – dietary calorie.
Devices used in measuring Heat Energy
Standard calorimeter
Bomb calorimeter

7. 2-1 Energy Converting units of energy
1 cal = J
1 Cal = 1000 cal
1 kJ = 1000 J
How many kJ are in 2.45 x 108 cal?

8. 2-1 Energy Practice: 1) Convert the following to calories (cal):
a) 900 J b) 2 Cal
2) Convert the following to joules (J):
a) 2.00 cal b) 220 Cal

9. 2-1 Energy Law of Conservation of Energy Energy Crisis
In any process, energy is neither created nor destroyed.
Energy Crisis
“Running out of energy?” How can it be?

10. 2-1 Energy Heat Capacity and Specific Heat
Heat Capacity – amount of heat needed to raise the temperature of a sample 1oC.
Units (J/oC)
Will change depending upon the mass of the object.
More mass more heat capacity.

11. 2-1 Energy Specific Heat Capacity
Amount of heat needed to raise the temperature of 1g of a substance by 1oC.
Larger value = Longer time to Heat
Specific Heat of Water = J/goC = 1 cal/goC
Cp = specific heat
q = heat
m = mass
T = change in temp

12. 2-1 Energy Heat Capacity vs. Specific Heat Capacity
Aluminum has a specific heat capacity of.899 J/goC.
How much heat will it take to raise 1 g of Al by 1oC?
.899J
Will 500g of Al or 100g have a greater heat capacity?
500g, more mass more heat capacity.
Will 500g of Al or 100g have a greater specific heat capacity?
Neither, aluminum always has a specific heat of .899j/goC

13. 2-1 Energy
What is the specific heat of a 550g substance, that gains 1200J of heat, as it increases in temperature from 25oC to 40oC?

14. 2-2 Temperature
Temperature – is the degree of hot or cold, determined by a thermometer.
Average kinetic energy of the particles in a sample.
Hot or Cold, are relative terms, dependent on a difference in temperature.

15. 2-2 Temperature Temperature Scales
Fahrenheit – Degreed scale based upon Gabriel Fahrenheit.
Water
Boils at 212oF
Freezes at 32oF
Celsius – Degreed scale based upon Anders Celsius. Metric system.
Boils at 100oC
Freezes at 0oC

16. 2-2 Temperature Temperature Scales
Kelvin – Absolute scaled, developed by William Thomson, Lord Kelvin.
Based upon Absolute Zero.
No negatives.
Lowest temperature possible, in theory.
Water
Boils at 373 K
Freezes at 273 K

17. 2-2 Temperature Converting temperatures: oC + 273 = kelvin
K – 273 = oC

18. 2-2 Temperature Sample Problems Convert the following to kelvins:
1) 100oC
2) –120oC
Convert the following to Celsius:
1) 100 K
2) 900 K

19. 2-2 Temperature Answers Problems Convert the following to kelvins:
Convert the following to Celsius:
1) –173oC
2) 627oC

20. 2-3 Matter
Anything that has mass and volume.

21. 2-3 Matter States of Matter Solid – definite shape, and volume.
Particles are tightly packed together, but still can vibrate or rotate.
Liquid – Indefinite shape but definite volume.
Particles are loosely spaced group, that move together.
Gases – Indefinite shape and volume.
Individualized particles that move rapid and randomly.
Plasma – Similar to gases but have charged particles.

23. 2-3 Matter Changes in States
Heating – makes the particles move faster.
Solid  Liquid  Gas  Plasma
Cooling – makes the particles move slower.
Plasma  Gas  Liquid  Solid

24. 2-3 Matter Properties – Characteristics that help describe an object.
Physical Properties – only describe the outer appearance of an object.
Will not alter the object.
Color, size, shape, mass, etc.
Chemical Properties – describes the internal make-up of an object.
Alters the object.
Chemical reactions: flammability, solubility, decomposition, etc.

25. 2-3 Matter Changes in Matter
Physical Change – Alters the outer appearance of a substance without changing what it is.
Chemical Change – Alters the internal make-up of a substance, it is no longer the same substance.

26. 2-3 Matter Indications of chemical change
Light or Heat (release of energy)
Bubbles or gas
Formation of a solid from a solution.
Precipitate (PPT)

27. 2-3 Matter Conservation of Matter
Matter, like energy, can’t be created nor destroyed in any process.

28. 2-4 Pure Substance
Homogeneous sample of matter, that can not be separated by physical means.
Can only, if at all, be separated by chemical means.

29. 2-4 Pure Substance Elements
Substance that can not be separated into simpler substances by physical or chemical change.
1 – 2 letter symbol, 1st letter is always capitalized.
Symbol is normally the 1st or 1st +2nd letters of the elements English or Latin name.

30. 2-4 Pure Substance Compounds
Substance that contains two or more elements, which can be separated by chemical change.
Identifying elements in a compound
Every capital letter indicates a new element.
Na2CO3
Na – Sodium, C – Carbon, and O - Oxygen

31. 2-4 Pure Substance Practice:
Identify the number and type of elements in the following compounds:
1) NaC2H3O2
2) PbCl2
3) KMnO4
4) HClO3
1) 1 Sodium, 2 Carbon, 3 Hydrogen, 2 Oxygen
2) 1 Lead, 2 Chlorine
3) 1 Potassium, 1 Manganese, 4 Oxygen
4) 1 Hydrogen, 1 Chlorine, 3 Oxygen

32. 2-4 Pure Substance Law of Definite Composition
A compound has the same ratio of elements by mass, no matter how large of a sample given.
Example – Sugar has
42.1% Carbon
51.4% Oxygen
06.5% Hydrogen by mass.

33. 2-5 Mixtures
Blend of two or more pure substances, by which each can be obtained through a physical separation.

34. 2-5 Mixtures Heterogeneous Homogeneous (Solutions)
Mixture that has two or more “phases,” or visible different parts.
Homogeneous (Solutions)
Mixture that has only one phase.
Stainless Steel
Carbon, Iron, Nickel, & Chromium

35. 2-5 Mixtures Separation of mixtures Filtration Distillation
Crystallization
Chromatography
Physical property (ex. Magnetic)

36. 2-5 Mixtures Summary of Matter Matter can be classified as:
Pure Substances
Mixtures
Differences in the two types of matter:
Whether it can be separated physically or chemically, if at all.

37. Chapter 2 Summary Matter NO Can be separated physically? YES
Pure Substance
Mixture
One Phase?
Can be separated chemically?
YES NO
YES NO
Elements
Compounds
Homogeneous
Heterogeneous

38. Granite
Plastic and water
Heterogeneous mixture
Heterogeneous mixture
Solid Gold
Pure Substance (element)
Brass
Homogeneous mixture
Gold Ore
Iron Sulfide
Pure Substance (compound)
Heterogeneous mixture

39. Origins of Element Symbols
11 Elements have an atomic symbol that doesn’t seem to match their name.
Originally named in Latin
Na – Sodium (Natrium)
K – Potassium (Kalium)
Fe – Iron (Ferrum)
Pb – Lead (Plumbum)
Au - Gold (Aurum)
Ag – Silver (Argentum)
Sn – Tin (Stannum)
Hg – Mercury (Hydrargyrum)
Sb – Antimony (Stibium)
Cu – Copper (Cuprum)
One originally named in Germany
W – Tungsten (Wolfram)