420 likes | 555 Vues
Matter and Energy. Applied Chemistry. Matter and Energy. The universe is made of matter and energy . Energy Definition: The capacity to do work or produce heat . Common unit: calorie abbreviated cal SI unit: Joule abbreviated J. Types of Energy.
E N D
Matter and Energy Applied Chemistry
Matter and Energy • The universe is made of matter and energy. • Energy • Definition: The capacity to do work or produce heat. • Common unit: calorie abbreviated cal • SI unit: Joule abbreviated J
Types of Energy • Radiant Energy is energy transferred through waves without matter. • Ex. Sunlight • Kinetic Energy is energy of motion. • Walking, Running, Water flowing • Potential Energy is energy of position or stored energy. • Ball at the top of a hill, battery
Forms of Energy Mechanical, Heat, Chemical, Electrical, Radiant, Sound, Nuclear
Law of Conservation of Energy • Energy is neither created nor destroyed. • Energy can change from one form to another.
Matter • Definition: anything that has mass and volume. • States of matter: • Solid s • Liquid l • Gas g • Plasma -----
Matter • Change is state is also known as a phase change. Temperature vs. Heat Animation
States of Matter Solid deposition melting sublimation freezing condensing evaporating Liquid Gas
Properties or Characteristics of Matter • A physical property is a property observed or measured without changing the material. • Example: color, density, shape, melting point, boiling point • A chemical property is a property that refers to the ability of a material to undergo a change that alters its structure. • Examples: flammability, light sensitivity
Changes in Matter • All changes involve a change in energy. • Physical changes: Do NOT change the identity of a substance. • Ex) size, shape, state, and dissolving • Chemical changes: Do change the identity of a substance. • Ex) burning, digesting food, rusting
Signs of a chemical change • Change in color • Formation of a precipitate (cloudiness; solid formed from 2 solutions) • Production of a gas (bubbles; fizzing) • Increase or decrease in temperature • Change or production of an odor
Chemical Equation – a shorthand way to • write a chemical change • Starting materials are called reactants • Newly formed materials are called products • Reactants products yields Iron + Oxygen Rust
Law of Conservation of Matter • Matter is neither created nor destroyed. • Shown by the French chemist Antoine Lavoisier in the 1700s. He is known as the Father of Chemistry. mass of reactants = mass of products
Elements • Contain only 1 type of atom. • Cannot be broken down by ordinary means. (physical or chemical) • Ancient Greeks believed there were only 4 elements. (earth, air, fire, and water) • 92 naturally occurring elements. Others are short-lived, man-made elements.
Elements • A symbol is a shorthand way of writing the name of an element. represents 1 atom of an element • Consists of 1 or 2 letters. • 1st letter is ALWAYS capitalized. • Subsequent letter is lower case. • 3-letter symbols are temporary designations assigned by IUPAC.
Elements • Using your periodic table, find the symbols for the following elements: • Hydrogen • Helium • Carbon • Chlorine • The number of elements as a solid, liquid, or gas at room temperature • 2 liquids • 11 gases • Others are solids H He C Cl
Compounds • Contain 2 or more different elements that are chemically combined. • Can be broken down by chemical processes, such as heat and electricity. • Smallest part of a compound is a molecule.
Compounds • A formula is a shorthand way of writing the name of a compound. It shows… • Which elements are present • The ratio of the elements present.
Examples of Formulas • H2O: the 2 is called a subscript that tells you that 2 atoms of hydrogen combine with 1 atom of oxygen to form 1 molecule of water. • 3H2O is read as 3 molecules of water. The 3 is called the coefficient. There are 6 hydrogen atoms and 3 oxygen atoms
Identify the following substances as elements or compounds. • Co Element • CS Compound • CO Compound • Mg Element • Note: If two capital letters are present, it is a compound.
Counting Atoms in Compound • Step 1: List all elements present • Step 2: Identify the coefficient • Step 3: Count the number of atoms of each element in the compound. • Step 4: Multiply the coefficient by the subscript • Step 5: Add up all the atoms
Counting Atoms • Na2SO4 7 atoms • Ca(OH)25 atoms • 3 Fe2(SO3)342 atoms
Mixtures • Mixtures contain elements or compounds that are mixed together but not chemically joined. • Types of Mixtures • Homogeneous Mixture or Solution • Heterogeneous Mixture or Mechanical Mixture
Homogeneous Mixtures • Uniform throughout • Not visibly different • Examples: • Gasoline • Food coloring • 14 caret gold • Air • Brass • lemonade
Examples of Alloys Brass is an alloy of copper and zinc. Steel is an alloy of carbon and iron. Bronze is an alloy of copper and tin.
Heterogeneous Mixtures • Not uniform throughout • Visibly different • Examples: • Oil & vinegar • Salad • Concrete • Soup • Sand and water
Separationof Heterogeneous Mixtures:Filtration • Separate suspended particles from a clear liquid by pouring through a screen, filter, or porous substance. • Filtrate: the liquid that passes through the filter • Residue: the solid left on the filter • Examples: car filter, pool filter
Separation of Heterogeneous Mixtures: Magnetic Method & Decanting • Magnetic Method • Separate magnetic substances from nonmagnetic substances. • Examples: iron filings and sulfur recycling center • Decanting • Separate liquids due to a difference in density • Example: oil from water
Separation of Homogeneous Mixtures: Chromotography • Separate pigments of ink using strips of paper. • Remember Pete Cheat Lab • Examples: dyes and chlorophyll
Separation of Homogeneous Mixtures: Distillation • Separate solution by a difference in boiling point. The liquids will evaporate and then condense back to a liquid. • Ex. Salt water, crude oil • Distillation Demo • A Closer Look at Distillation
Separation of Homogeneous Mixtures: Crystallization • Separate a solution by evaporating the liquid and the solid will recrystallize. • Examples: rock candy, salt water