2. 1 What is CHEMISTRY ? What is CHEMISTRY ? The Study of
CHAPTER
The Study of
Matter and its Properties,
the Changes that
Matter Undergoes,
and the Energy
Associated with
those Changes

3. Major Chemistry subdivisions1
Major Chemistry subdivisions
CHAPTER
Analytical (qualitative and quantitative) Chemistry:
Qualitative Analytical Chemistry: What is a sample of matter composed of?
Quantitative Analytical Chemistry: How much “stuff” is in a sample of matter?
Physical Chemistry:
The study of the physics involved with chemical changes.
Organic Chemistry:
The study of properties and reactions of compounds that contain Carbon
Inorganic Chemistry:
The study of properties and reactions of compounds that are not Carbon based
Biochemistry: The study of living systems (Biology + Chemistry)

4. 1 From experiment to modelling Levels of Operation
Chemistry: The Study of Change
CHAPTER
Levels of Operation
From experiment to modelling
“Chemists communicate their observations and ideas with each other through words, labels, drawings and symbols to refer to particular events and substances”

5. 1 Matter is defined as: Anything that occupies space and has mass
Chemistry: The Study of Change
CHAPTER
Classifying Matter
Matter is defined as: Anything that occupies space and has mass
The classification of matter include substances, mixtures, elements, and compounds, as well as atoms and molecules.
Mass: The quantity of matter in a material.
Law of Conservation of Mass:
The total mass remains constant during a chemical change (chemical reaction).

6. 1 Solid: characterized by rigidity; fixed volume and fixed shape.
Chemistry: The Study of Change
CHAPTER
States of Matter
Solid: characterized by rigidity; fixed volume and fixed shape.
Liquid: relatively incompressible fluid; fixed volume, no fixed shape.
Gas: compressible fluid; no fixed volume, no fixed shape.
Particles are closely packed
and vibrate about fixed positions
Particles are not in fixed positions and
can move past one another
Particles are not in fixed positions and
can move past one another

7. 1 Substance: is a single, pure form of matter
Chemistry: The Study of Change
CHAPTER
Classifying Matter
Substance: is a single, pure form of matter
Example: water, copper, sugar, Oxygen and gold
Or, A kind of matter that cannot be separated into other kinds of matter by any physical process such as distillation or sublimation.
Mixtures contain two of more substances mixed together
Example: air, steel, soda-cola, saltwater, salad dressing
Mixtures can be:
Homogeneous mixtures
Heterogeneous mixtures

8. 1 Homogeneous and heterogeneous mixtures Classifying Matter
Chemistry: The Study of Change
CHAPTER
Classifying Matter
Homogeneous and heterogeneous mixtures
A solution of salt in water is a homogeneous mixture or sugar dissolves in water , The sample has a uniform composition throughout
Noodle soup is a heterogeneous mixture
Materials are not uniformly dispersed over the whole sample

9. 1 Elements and their Atoms
Chemistry: The Study of Change
CHAPTER
Elements and their Atoms
Element: A substance that cannot be decomposed into simpler substances by any chemical reaction.
There are only 118 (so far) known elements
90 elements are found in nature, the rest have been made in the laboratory
Example of elements:

10. 1
Chemistry: The Study of Change
CHAPTER
Compounds and Molecules
A molecule is formed when two or more atoms join together chemically.
A compound is a molecule that contains at least two different elements.
All compounds are molecules but not all molecules are compounds.
Molecules H2 O2
Compounds
NaCl
CH4
CaCl2

11. 1
Chemistry: The Study of Change
CHAPTER
Compounds
A CHEMICAL COMPOUND is a substance composed of atoms of two or more different elements. H2O or CO2
A combination of atoms represents a MOLECULE or ION, which is characteristic for each compound
Molecules or ions are composed of atoms in fixed and definite proportions
Compounds have properties which are different than properties of elements they are made from

12. 1
Chemistry: The Study of Change
CHAPTER
Compounds
EXAMPLE: Sodium (metal) and chlorine (gas) will react to produce sodium chloride NaCl (table salt – colourless, crystalline substance):

13. 1
Chemistry: The Study of Change
CHAPTER
Compounds
A CHEMICAL FORMULA shows the composition of a compound
It features the relative numbers of different types of atoms
EXAMPLE:
NaCl
Sodium chloride contains
the same number of atoms
of sodium and chlorine
combined in a molecule Na Cl

15. 1 Kinetic-molecular model of matter Classifying Matter
Chemistry: The Study of Change
CHAPTER
Classifying Matter
Kinetic-molecular model of matter
Particles: atoms, molecules or ions
Motion of particles opposed by the forces of attraction between particles
SOLID
LIQUID
GAS
Forces of attraction dominate
Fast motion of particles due to the increase in kinetic energy. Resulting forces overcome forces of attraction
Temperature increases

16. 1
Chemistry: The Study of Change
CHAPTER
Chemical Reactions, Chemical Change
Aluminum powder burns in oxygen to produce a substance called aluminum oxide. A sample of 2.00 grams of aluminum is burned in oxygen and produces 3.78 grams of aluminum oxide. How many grams of oxygen were used in this reaction?
aluminum + oxygen = aluminum oxide
2.00 g + oxygen = 3.78 g
oxygen = 1.78 g

17. Comparison of Physical and Chemical Properties

18. 1 Introduction Chemistry: The Study of Change Classification of Matter
CHAPTER
Introduction
Classification of Matter
Matter is anything that occupies space and has mass. The classification of matter include substances, mixtures, elements, and compounds, as well as atoms and molecules.
Substances and Mixtures:
A Substance is a form of matter that has a definite (constant) composition and distinct properties. Examples are water, ammonia, gold and oxygen.
A Mixture is a combination of two or more substances in the substances retain their distinct identities. Examples are air, and cement.
Mixtures are either homogeneous or heterogeneous. When a spoonful of sugar dissolves in water we obtain a homogenous mixture in which the composition of the mixture is the same throughout. If sand is mixed with iron filings, however, the sand grains remain separate. This type of mixture is called a heterogeneous mixture because the composition is not uniform.

19. Any type of mixture, can be created and then separated by physical means into pure component.
Solution: Is a homogeneous mixture and its components called :
Solute : it is the existent substance in a low quantity.
Solvent: it is the existent substance in a high quantity.
Elements and Compounds
An element is a substance that cannot be separated into simpler substances.
To date, 117 elements have been identified.
Atoms of most elements can interact with one another to form compounds.
Hydrogen gas, for example, burns in oxygen gas to form water, which has
properties that are different from those of the starting materials.

20. 1
Chemistry: The Study of Change
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Measurements
A measured quantity is usually written as a number with an appropriate unit. Examples 20 grams 6.63 × 10–34 joule·seconds
SI Units
In 1960 the General Conference of Weights and Measures, the international authority of units, proposed a revised metric system called international system of units (abbreviated SI . Table 1.2 shows the seven SI base units. All other units of measurements can be derived from these base units. SI units are modified in decimal fashion by a series of prefixes, as shown in table 1.3

21. 1
Chemistry: The Study of Change
CHAPTER
Measurements

22. 1 Measurements Chemistry: The Study of Change
CHAPTER
Measurements
femto f femtometer fm = 1 x m

23. 1
Chemistry: The Study of Change
CHAPTER
Measurements
Note that a metric prefix simply represents a number: mm = 1 x 10-3 m Measurements that we will utilize frequently in our study of chemistry include time, mass, volume, and temperature.

24. 1
Chemistry: The Study of Change
CHAPTER
Measurement
Mass and Weight Mass is a measure of the amount of matter in an object, weight, is the force that gravity exerts on an object. An apple that falls from a tree is pulled downward by Earth`s gravity. The mass of the apple is constant and does not depend on its location, but its weight does. Chemists are interested in mass, which can be determined with a balance. The SI unit of mass is kilogram (Kg) Kg g = 1 x 103 g

25. CHEMISTRY 110 Prepared By, Dr. Khalid Ahmad Shadid
Volume V = length x width x height = m x m x m = m3 The SI unite of length is the meter (m), and that of volume is the cubic meter (m3), the cubic centimeter (cm3) and the cubic decimeter (dm3) 1cm3 = ( 1 x 10-2 m )3 = 1 x 10-6 m dm3 = ( 1 x 10-1 m)3 = 1 x 10-3 m3 Another common unite of volume is the liter (L) 1L = 1000 ml = cm = 1 dm3
1 mL = 1 cm3.

26. Density The equation for density is The SI-derived unit for density is the kilogram per cubic meter ( kg/m3 ). This unit is large for most chemical applications. Therefore, gram per cubic centimeter (g/cm3) and its equivalent, gram per milliliter (g/mL) are used for solid and liquid densities g/cm3 = 1g/mL = 1000kg/m3 Example 1.1 A piece of metal with a mass of 200 g has a volume of 17.6 cm3 . Calculate the density of gold. Solution: We are given the mass and volume and asked to calculate the density Example 1.2 The density of mercury, the only metal is a liquid at room temperature, is 13.6 g/ml. calculate the mass of 7.8 mL of the liquid. Solution:

27. Heat and Temperature Heat and Temperature are not the same thing
T is a measure of the intensity of heat in a body
3 common temperature scales - all use water as a reference

28. Temperature: Three temperature are currently in use
Temperature: Three temperature are currently in use. Their units are ⁰F(degrees Fahrenheit). ⁰C (degree s Celsius), and K (kelvin). The fahrenheit scale, defines the normal freezing and boiling points of water to be 32⁰F and 212⁰F, respectively. The Celsius scale divides the range between the freezing point (0⁰C) and boiling point (100⁰C) of water into 100 degrees. The kelvin is the SI base unite of temperature: it is the absolute temperature scale. T e zero on kelvin ( 0 K ) is the lowest temperature can be attained. To convert Fahrenheit we use K = ⁰C ,15

29. Heat and Temperature MP water BP water Fahrenheit 32 oF 212 oF
Celsius oC oC
Kelvin K K

30. Relationships of the Three Temperature Scales

31. Relationships of the Three Temperature Scales

32. Relationships of the Three Temperature Scales

33. Relationships of the Three Temperature Scales
Easy method to remember how to convert from Centigrade to Fahrenheit.
Double the Centigrade temperature.
Subtract 10% of the doubled number.
Add 32.

34. Temperature Example: Convert 211oF to degrees Celsius.
Example: Express 548 K in Celsius degrees.

35. Example 1.3 a) A certain solder (alloy of Tin & lead) has a melting point of 245⁰C. What is its melting point in degrees Fahrenheit? b) Helium has the lowest boiling points of all the elements at -396⁰F. Convert this temperature to degrees Celsius. c) Mercury, the only metal that exists as a liquid at room temperature, melts at -96.5⁰C , convert its melting point to kelvins. Solution: a) ⁰C = ( ⁰F – 32⁰F) x (245⁰C x 9⁰F ÷ 5⁰C ) + 32⁰F = ⁰F (245x 9⁰F ÷ 5 ) + 32⁰ F =473 ⁰F
c) K = ⁰C , = = K Other examples in “ summery of G. Chemistry” page 10

37. Handling Numbers Scientific Notation All numbers can be expressed in the form N x 10n where N is a number between 1 and 10 and n, the exponent, is a positive or negative integer(whole number). Any number expressed in this way is said to be written in scientific notation. e.g. 1) Express in scientific notation = x ) Express in scientific notation = 7.72 x 10-6

38. Significant Figures Any digit that is not zero is significant
1.234 kg significant figures
Zeros between nonzero digits are significant
606 m significant figures
sig figs.
Zeros to the left of the first nonzero digit are not significant
0.08 L significant figure

39. Significant Figures
If a number is greater than 1, then all zeros to the right of the decimal point are significant
2.0 mg significant figures
If a number is less than 1, then only the zeros that are at the end and in the middle of the number are significant
g 3 significant figures

40. 9.300 has 4 sig figs. 150 has 2 sig figs. 1000000 1 sig figs.
Trailing zeros are zeros at the right end of the number. They are significant only if the number contains a decimal point.
9.300 has 4 sig figs.
has 2 sig figs.
sig figs.
sig fig

41. Significant Figures
Exact numbers: have an INFINITE number of significant figures. This rule applies to numbers that are definitions.
For example, 1 meter = 1.00 meters = meters =  meters, etc.