Chapter 1/2 Chemistry and Matter

What is Chemistry? Chemistry is the study of matter and the changes that matter undergoes.   Because all things are made up of matter, chemistry affects all aspects of life.

Areas of Chemistry Organic Chemistry Inorganic Chemistry Biochemistry Analytical Chemistry Physical Chemistry

The Scientific Method Making Observation (leads to a question) Developing a Hypothesis Experiment (Test Hypothesis) Conclusion (Develop Theory or Scientific Law) Repeat experiment

Matter Matter: Anything that takes up space and has mass (inertia) Mass: The measure of the amount of matter that an object contains Properties of Matter: Describes the characteristics and behavior of matter, including the changes that matter undergoes  

Matter The Macroscopic View of Matter Matter that is large enough to be seen The Submicroscopic View of Matter So small that you cannot see it, even with the most powerful microscope The Microscopic View of Matter Small enough that a microscope is needed.

Extensive vs. Intensive An extensive property is a property that depends on the amount of matter in a sample. Ex. Mass, volume, length, etc. An intensive property is a property that depends on the type of matter in a sample, not the amount of matter. Ex. Color, Texture, density, etc.

Observations of matter Qualitative: made without measurement Ex. Color, texture, shape, etc. Quantitative: made with measurement Ex. Mass, volume, length, etc.

States of Matter SOLID LIQUID GAS Solid: a form of matter with definite shape and volume Liquid: a form of matter with a indefinite shape, but a definite volume Gas: a form of matter with an indefinite shape and volume SOLID LIQUID GAS Freezing Evaporation Melting Sublimation Condensation

Mixtures Mixture: A combination of two or more substances in which the basic identity of each substance is not changed. Mixtures can be classified as heterogeneous or homogeneous Heterogeneous Mixtures: A mixture that has a composition that is different throughout. Ex. Cookie Dough ice cream Homogeneous Mixtures: A mixture that has a composition that is the same throughout. Ex. Lemonade (solutions)

AQUEOUS SUGAR SOLUTION Solutions A solution is made up of a solute and a solvent Solute: The substance being dissolved Solvent: The substance doing the dissolving When the solvent is water the solution is said to be ‘AQUEOUS” (an aqueous solution.) = + SOLUTE SOLVENT SOLUTION = + SUGAR WATER AQUEOUS SUGAR SOLUTION

Separating Mixtures Differences in Physical properties can be used to separate mixtures. Filtration: a process that separates a solid from a liquid in a heterogeneous solution. Distillation: A liquid is boiled to produce a vapor which is then condensed into a liquid (used to separate a liquid from solids or to separate two liquids)

Elements vs. Compounds Element: simplest form of matter that has a unique set of properties. Compound: substance that contains two or more elements chemically combined Compounds can be broken down into simpler substances by chemical means, elements cannot.

Symbols Chemists use chemical symbols to represent elements, and chemical formulas to represent compounds Ex. Sodium = Na, Chlorine = Cl Ex. Sodium Chloride = NaCl

Matter MATTER MIXTURES PURE SUBSTANCES COMPOUNDS ELEMENTS PHYSICAL CHANGES HETEROGENEOUS MIXTURES HOMOGENEOUS MIXTURES COMPOUNDS ELEMENTS SALT, BAKING SODA, SUGAR OXYGEN, GOLD, IRON DIRT, BLOOD, MILK SODA, GASOLINE, AIR

= = Density MASS DENSITY VOLUME DENSITY The amount of matter (mass) contained in a unit volume. Measured in grams MASS = DENSITY VOLUME Measured in milliliters MASS per VOLUME -OR- GRAMS PER MILLILITER = DENSITY

Chemical vs. Physical Changes Physical Property: a quality or condition of a substance that can be observed or measured without changing the substance’s composition Ex. Solubility, melting point, boiling point, color, density, electrical conductivity, and physical state (solid, liquid, gas) During a physical change, the composition of matter always remains the same. Tearing, cutting, grinding Change of state: boil, freeze, melt, and condense

Chemical vs. Physical Changes Chemical Property: the ability of a substance to undergo a chemical change is called a chemical property Ex. Flammable, corrosive, ability to rust During a chemical change, the composition of matter always changes Ex.. burn, rot, rust, decompose, ferment, explode, corrode A chemical change is also called a chemical reaction. Possible indicators of a chemical change include: a transfer of energy a change in color the production of gas or the formation of a precipitate

Chemical Reactions and Energy the capacity to do work All chemical changes involve some sort of energy change. Energy is either given off ….“EXOTHERMIC” Or….taken in…. “ENDOTHERMIC” 

Law of Conservation of Mass and Energy The law of conservation of mass and energy states that both matter and energy cannot be created or destroyed in any process IT’S THE LAW!!!

Energy Energy is the capacity to do work or produce heat Kinetic Energy: Energy of Motion Potential Energy: Energy of Position (stored energy)