Chemistry
The study of the composition, structure, and properties of matter, the processes that matter undergoes, and the energy changes that accompany these process
Branches of Chemistry
1. Organic Chemistry
2. Inorganic Chemistry
3. Physical Chemistry
4. Analytical Chemistry
5. Biochemistry
6. Theoretical chemistry
Chemical
Any substance that has a definite composition
Basic Research
Carried out to increase knowledge
Applied Research
Carried out to solve a specific problem
Technological Development
The production and use of products that improve our quality of live
Volume
Amount of space an object occupies
Physical Property
Graduated Cylinder
SI unit - m�
Extensive Property
Mass
Measure of the amount of matter
Physical Property
Balance
SI unit - kilogram
Extensive Property
Matter
Anything that has mass and takes up space
(Solids, liquids, gases, plasmas and Bose-Einstein condensates (BEC))
Pure Substance
All particles are the same, have a fixed composition
Elements or compounds
Classifying Matter
Matter
?
Solids, Liquids, and Gases
?
Pure Substances ? Mixtures
? ?
Elements and Homogeneous and
Compounds Heterogeneous mixtures
Atom
The smallest unit of an element that maintains the chemical identity of that element
Element
A pure substance that cannot be broken down into simpler, stable substances and is made of on type of atom
(ex. oxygen, hydrogen, carbon, helium, iron, calcium, etc.)
Compound
A substance that can be broken down into simple stable substances. Each compound is made from the atoms of two or more elements that are chemically bonded
(ex. sugar, pure water, baking soda, salt, glass, carbon-dioxide )
Extensive Properties
Depend on the amount of matter that is present
(ex. volume, mass, length, amount of energy in a substance, etc.)
Intensive Properties
Do not depend on the amount of matter present
(ex. melting point, boiling point, density, ability to conduct electricity and to transfer energy as heat, etc)
Physical Change
A change in a substance that does not involve a change in the identity of the substance
(ex. grinding, cutting, melting, boiling, etc)
Change of State
Physical change of a substance from one state to another
Mixture
A blend of two or more kinds of matter, each of which retains its own identity and properties
Homogeneous Mixture
Also called solutions, have the same appearance and composition throughout and may be a solid, liquid, or gas
(ex. air, sugar water orange juice, alcohol in water, cup of coffee, brass, etc.)
Heterogeneous Mixture
Do not have the same appearance, composition varies
(ex. oil and water blood, sand and sugar mixed nuts, pizza, soil, etc.)
Solid
Definite shape and definite volume
Almost incompressible
Slightly expands on heating
Molecules closest together (packed)
Highest density
(ex. ice, pennies, etc.)
Liquid
Indefinite shape and definite volume
Almost incompressible
Slightly expands on heating
Molecules close, but not rigidly packed
Lower density than solids, but higher than gas
(ex. water, soda, etc.)
Gas
Indefinite shape and indefinite volume
Great compressibility
Greatly expands on heating
Molecules far apart
Lowest density of the three
(ex. air, helium, etc.)
Plasma
High-temperature physical state of matter in which atoms lose most of their electrons, particles that make up atoms
Chemical Property
A substance's ability to undergo changes that transforms it into different substances
(ex. flammability, ability to spoil, reacts with water to form a gas, can neutralize a base, etc.)
Chemical Change
Or chemical reaction, a change in which one or more substances are converted into different substances
(ex. decomposing, rusting, reactivity, corrosion, etc.)
Reactants
The substances that react in a chemical reaction
Products
The substances that are formed by the chemical change
The Law of Conservation of Energy
States that although energy can be absorbed or released in a change, it is not created or destroyed, but assumes a different form.
How do pure substances differ from mixtures?
1. Every sample of a given pure substance has exactly the same characteristic properties. The properties of a mixture depend on the relative amounts of the mixture's composition
2. Every sample of a pure substance has exactly the same composition
Qualitative Observation
Description using your 5 senses
Quantitive Observation
Involves using measurements and numerical data
Measured Values
Mass (gm) - balance
Volume (mL= cubic cm) - graduated cylinder
Precision
Reproducibility of a measurement
A measuring tool with smaller measurement intervals - more precise
precise ? accurate
Accuracy
Closeness to the accepted value, the quality of nearness to the truth or the true value
Length
Distance - meters
Temperature
Hotness or coldness, the degree of hotness or coldness of a body or environment (corresponding to its molecular activity) - thermometer
Time
Sec
Density
Mass per unit volume
Intensive Property
Degree of compactness
D = M/V
V = M/D
M = D x V
Pressure
P = Force/Area unit mmHg
Estimation
Confidence in precision
Significant Figures
Also called significant digits, any none zero number
*See unit packet for rules
Quantity
Something that has magnitude, size, or amount
SI
Single measurement system used worldwide
Weight
Measure of the gravitational pull on matter
Derived Units
Combinations of SI base units
Percentage Error
Calculated by subtracting the accepted value from the experimental value, dividing the difference by the accepted value, and then multiplying by 100
Scientific Notation
Numbers are written in the form M x 10?
Thermochemistry
The study of the transfers of energy as heat that accompany chemical reactions and physical changes
Calorimeter
The energy absorbed or released as heat in a chemical or physical change
Temperature
The measure of the average kinetic energy of the particles in a sample of matter
Joule
The SI unit of heat as well as all other forms of energy
Heat
The energy transferred between samples of matter because of a difference in their temperatures
Specific Heat
The amount of energy required to raise the temperature of one gram of a substance by one Celsius degree (1�C) or one Kelvin (1K)
Enthalpy Change
The amount of energy absorbed by a system as heat during a process at constant enthalpy
Enthalpy = H products - H reactants
Endothermic
Energy is absorbed
Cooling process
Exothermic
Energy is released
Heating process
Photosynthesis
Process plants undergo to produce glucose by using water, carbon dioxide, and sunlight
Endothermic
6CO?+6H?O + energy ? C?H??O? + 6O?
Cellular Respiration
Reaction in which cells transform the food you eat into a form of energy (ATP) that is useable by your cells
Exothermic
C?H??O? + 6O? ? 6CO?+6H?O + energy
Law of Conservation of Mass
States that in any chemical reaction or physical process, mass cannot be created or destroyed but can be transformed from one form to another
Compressibility
Capable of being easily compressed, , the property of being able to occupy less space
Conductivity
The transmission of heat or electricity or sound
Corrosion
A substance having the tendency to cause corrosion (such a strong acids or alkali)
Heat Calculations
Q=mC?T
Q - energy lost or gained - heat (J or Cal)
M - mass (g)
C - specific heat
?T - change in temperature (?T=?TF-?T)
Density of Water
1 g/cm�
Specific Heat of Water
4.18 J/g�C
G.U.E.S.S
Given
Unknown
Equation
Substitute
Solve & Sig Figs
Metric System
Kilo - 1 thousand
Hecto - 1 hundred
Deka - 1 ten
Base Unit - m, L, g
Deci - 1 tenth
Centi - 1 hundredth
Milli - 1 thousandth
Micro - 1 millionth
Nano - 1 billionth
Directly Proportional
Two quantities are directly proportional to each other id dividing one by the other gives a constant value
Y/X = K
Inversely Proportional
Two quantitates are inversely proportional to each other id their product is constant
XY = K