CHEMISTRY STUDY GUIDE 1045 Exam 2 SOLUBILITY RULES It is soluble if it dissolves in water and it is insoluble if it does not dissolve in water Compounds that are soluble Li Na K and NH NO Cl Br and I 3 and C2H3O 2 4 SO2 4 Compounds that are insoluble OH and S2 CO2 3 and PO3 4 Exceptions None None When these ions pair with Ag Pb2 or Hg2 compound is insoluble When SO2 Pb2 Ag or Ca2 the resulting compound is insoluble 2 the resulting 4 pairs with Sr2 Ba2 Exceptions 1 When these ions pair with Li Na K or NH 4 the resulting compound is soluble 2 When S2 pairs with Ca2 Sr2 or Ba2 the resulting compound is soluble 3 When OH pairs with Ca2 Sr2 or Ba2 the resulting compound is slightly soluble When these ions pair with Li Na K or NH 4 the resulting compounds are soluble Acid Base Reactions Neutralization reaction NaOH is a common base Acid Base reaction An acid reacts with a base and the two neutralize each other producing water or a weak electrolyte Bases substances that produce hydroxide OH ions in water aqueous solution Acid substances that produce H ions in aqueous solutions HCl is a common acid When an acid and base mix the H from the acid combines with the OH from the base to form H2O These reactions normally form water and a salt ionic compound Acid Base Water Salt acid base reaction Example HCl aq NaOH aq H2O l NaCl aq List of common acids and bases Name of Acid Hydrochloric Acid Hydrobromic Acid Hydroiodic Acid Nitric Acid Sulfuric Acid Perchloric Acid Acetic Acid Hydrofluoric Acid Name of Base Sodium Hydroxide Lithium Hydroxide Potassium Hydroxide Calcium Hydroxide Barium Hydroxide Ammonia Formula HCl HBr HI HNO3 H2SO4 HClO4 HC2H3O2 weak acid HF weak acid Formula NaOH LiOH KOH Ca OH 2 Ba OH 2 NH3 weak base Redox Reactions Oxidation reduction reactions redox reactions are reactions in which electrons are transferred from one reactant to the other Sometimes involve the reaction of a substance with oxygen Metals have a tendency to lose electrons Non metals have a tendency to gain electrons Oxidation loss of electrons Reduction gain of electrons Oxidation state the charge it In both cases metal atoms lose electrons to non metal atoms would have if all shared electrons were assigned to the atom with a greater attraction for those electrons OILRIG oxidation is loss reduction is gain Rules for assigning oxidation states Oxidation state of an atom in a free element is 0 Oxidation state of a monoatomic ion is equal to its charge Sum of oxidation states of all atoms in 1 a neutral molecule or formula unit is 0 2 an ion is equal to the charge of the ion Examples Cu Cl2 Ca2 Cl 1 H2O 2 NO 3 In their compounds metals have positive oxidation states 1 Group 1A metals ALWAYS have oxidation state of 1 2 Group 2A metals ALWAYS have oxidation state of 2 Nonmetals are assigned oxidations according to the table below LOOK BELOW 1 NaCl 2 CaF2 Nonmetal Fluorine Hydrogen Oxygen Group 7A Group 6A Group 5A Oxidation state 1 1 2 1 2 3 Example MgF2 H2O CO2 CCl4 H2S NH3 a redox In order to identify reaction know Oxidation is an increase in oxidation state Reduction is a decrease in oxidation state Oxygen is an example of oxidizing agent Hydrogen is an example of reducing agent Quantum Mechanics The theory suggested that for subatomic particles electrons neurons and protons the present does NOT completely determine the future Foundation of chemistry explains periodic table explains behavior of the elements in chemical bonding provides practical basis for lasers computers and other applications Quantum mechanical model explains how electrons exist in atoms and how those electrons determine the chemical and physical properties of elements Amplitude vertical height of a crest determines the intensity of light Wavelength distance in space between adjacent crests measured in units of distance meter micrometer nanometer determines color Frequency v or Hz the number of cycles that pass through a stationary point in a given period of time Photoelectric effect was the observation that many metals emit electrons when light shines upon them In 1905 Einstein proposed that light energy must come in packets These packets are called photons Table of Constants Constant Value c h Equations 3 00 x 108 m s 6 6 x 10 34 J s 1 Energy of photon 2 Frequency E hc c E hv 3 Energy in a light packet 4 Energy of an orbital En 2 18 10 18 J 1 n2 5 Energy difference corresponding to the transition from n to n 6 Wavelength of an electron of mass m moving at velocity v Eatom E n En h mv Quantum Mechanics and the Atom Quantum numbers n the principle quantum number The angular momentum quantum number l The magnetic quantum number ml Value of l Letter l 0 l 1 l 2 l 3 S P D F Electron Configuration An electron configuration for an atom simply shows which quantum mechanical orbitals are occupied by the atom s electrons Order of filling out quantum mechanical orbitals 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s Size of an Atom radii As you move down a column in the periodic table there are larger atomic As you move across a row in the periodic table atomic radii decrease The radius of a cation is much smaller than that of the corresponding atom The radius of an anion is much larger than that of the corresponding atom Ionization energy decreases as you move down a column in the periodic table Ionization energy increases as you move to the right and across a row Ionization energy the energy required to remove an electron from an atom in the gaseous state Electron Affinity the energy associated with an element in its gaseous state gaining an electron Becomes more negative to the right across a row exothermic Metallic Character the tendency to lose electrons in a chemical reaction Increases down a column in the periodic table and decreases to the right across a row Electronegativity the ability of an atom to attract electrons to itself in a chemical bond Fluorine Hydrogen when it comes to electronegativity Lanthanide Contractions Why is Zr HF The lanthanide contraction describes the steady decrease in the size of the atoms and ions from Lanthanum to Lutetium The radius goes from high to low as we move across the periodic table in which case Zr is greater than HF People to Know 1 Johannes Rydberg analyzed many atomic spectra and developed a simple 2 Johann Dobereiner 1780 1849 grouped elements intro triads 3elements 3 John Newlands 1837 1898 organized elements into octaves in analogy to equation with similar properties musical notes periodic table 4 Dmitri
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