1. Lecture 2: Matter and Energy
Chemistry - SPRING 2017
Course lecturer :
Jasmin Šutković
27th February 2017

2. Contents Units of Measurements- Wednesday! Matter and Energy
International University of Sarajevo
Units of Measurements- Wednesday!
Matter and Energy
Classification of matter
States of matter
Temperature
Energy and Nutrition

3. What is Matter ?
Matter is anything that occupies space and possesses MASS.
People, Gold, Smoke, Smog and so on…..
NOT MATTER : light and sound!
Many people mix-up MASS and Weight .

4. Object MASS is not its WEIGHT !!!
MASS is a measurement of the amount of matter something contains, while WEIGHT is the measurement of the pull of gravity on an object.
Matter does not depend on the location of an object but Weight does !!!
Example: On the Moon, your MASS will be the same, but your WEIGHT will be different since the Moon doesn't have the same gravity as the Earth.

5. States of Matter ?
Under normal conditions there are three distinct states of matter :
Solids – rigid and fixes shape
Liquids – fixed volumes and take the shape of their containers
Gases – have neither fixed shape nor fixed volume and fill their container completely
Figure 3. Example of states of matter

7. Pure Substances: Elements and Compounds
A pure substance is matter that has a fixed or definite composition.
There are two kinds of pure substances: elements and compounds.
An element, the simplest type of a pure substance, is composed of only one type of material such as silver, iron, or aluminum
A compound is also a pure substance, but it consists of atoms of two or more elements always chemically combined in the same proportion. In compounds, the atoms are held together by attractions called bonds, which form small groups of atoms called molecules.

8. Compound: H2O
For example, a molecule of the compound water has two hydrogen atoms for every one oxygen atom and is represented by the formula H2O.
This means that water found anywhere always has the same composition of H2O.

9. Rule ...
Pure substances CAN NOT be broken down into smaller peaces but compounds as water or salt can !

10. Mixtures
Mixture — combinations of two or more pure substances in variable proportions in which the individual substances retain their identity
1. Homogeneous mixtures
a. All portions of a material are in the same state, have no visible boundaries
b. Also called SOLUTIONS
2. Heterogeneous mixtures
a. Composition of a material is not completely uniform

11. Properties of Matter
Properties used to describe material substances can be classified as either physical or chemical.
Physical properties:
Characteristics that scientists can measure without changing the composition of the sample under study (mass, color, volume, amount of space occupied by the sample).
Chemical properties:
Describe the characteristic ability of a substance to react to form new substances (flammability and corrosion).

14. Examples of Physical and Chemical changes

15. Measure unit is Celsius (C)...in the USA it is the Fahrenheit (F).
Temperature
Measure unit is Celsius (C)...in the USA it is the Fahrenheit (F).
1C =1.8F

16. Kelvin : one more measure for temperature – absolute scale!
The lowest temperature on earth is C, which equals 0 Kelvin (absolute zero)
1C= 273K

19. Variation in Body temperature

20. What ever we do requires energy....!
Energy is defined as the ability to do work.
We have to forms of energy and
these are :

21. Kinetic and Potential energy
Motion energy! Whatever moves has kinetic energy.
Energy that is stored or kept until movement, determined by the position of the object that has the potential energy !

23. More examples ???
When you digest food or burn gasoline in your car, potential energy is converted to kinetic energy to do work.

24. Heat and Energy
Heat is the energy associated with the motion of particles.
An ice cube feels cold. Because heat flows from your hand into the ice cube. The faster the particles move, the greater the heat or thermal energy of the substance.
In the ice cube, the particles are moving very slowly. As heat is added, the motions of the particles in the ice cube increase. Eventually, the particles have enough energy to make the ice cube melt as it changes from a solid to a liquid.

25. The SI unit or metric system unit for energy is Joule (J).
Units of Energy
The SI unit or metric system unit for energy is Joule (J).
You may be more familiar with the unit calorie (cal), from the Latin caloric, meaning “heat.”
The International System of Units (SI) , or Système International, is the official system of measurement throughout the world except for the United States.

26. Units

27. Chemistry link to Environment

28. Energy and Nutrition
Food = energy (sugars, fats, proteins)
Used units for nutritional measurement is calorie or Cal.
The international unit is KJ (kilojoules), more prevalent.

30. 1 ounce (oz) is 28.35g

32. Link to health

33. Specific heat
Everyone absorbs heat differently (every substance does it differently)
The specific heat (SH) is the amount of heat needed to raise the temperature 1g of substance by 1C.
Temperature change is called as delta T ( ∆T), where ∆ means change in!

35. Calculation in regards to ∆H

36. Changes of state

37. Today's lecture: book chapter 3
Pages: 57-76
HW1: Page 75, Problems 3.33 and 3.36 Page 83, Problems 3.39 and 3.40,
Submittion by 5th March-late homeworkks not accepted