Chem 101 Review. Fall PDF Free Download

Chem 101 Review Fall 2012

Elements, Atoms, Ions Elements in nature symbols Constant composition chemical formula Dalton s atomic theory Atomic structure what makes up the atom ions isotopes Periodic table

Elements, Atoms, Ions Elements in nature symbols Constant composition chemical formula Dalton s atomic theory Atomic structure what makes up the atom ions isotopes Periodic table A compound always has the same composition Represented by a formula that gives the relative number of atoms in the compound Carbon dioxide CO 2

Elements, Atoms, Ions Elements in nature symbols Constant composition chemical formula Dalton s atomic theory Atomic structure what makes up the atom ions isotopes Periodic table All elements are composed of atoms. All atoms in an element are identical, Atoms of different elements are different. Atoms combine to form chemical compounds. Atoms are not created or destroyed in chemical reactions.

Elements, Atoms, Ions Elements in nature symbols Constant composition chemical formula Dalton s atomic theory Atomic structure what makes up the atom ions isotopes Periodic table

Elements, Atoms, Ions Elements in nature symbols Constant composition chemical formula Dalton s atomic theory Atomic structure Positive and negative ions combine to form ionic compounds. The net charge for the compound is 0. Al 3+ + N 3- AlN what makes up the atom ions isotopes Periodic table

Elements, Atoms, Ions Elements in nature symbols Constant composition chemical formula Dalton s atomic theory Atomic structure what makes up the atom ions isotopes Periodic table

Periodic table Elements Whats in the box? symbol and name atomic number (#p = #e) atomic mass (#p = #n) metals and nonmetals group, column, family principal energy level relative atomic size relative ionization energy relative reactivity relative electronegativity Ions charge on common ions 11 Na 23 22 Na 11 vs 23 Na 11 22 Na

Elements symbol and name atomic number (#p=#e) atomic mass (#p = #n) metals and nonmetals group, column, family principal energy level relative atomic size relative ionization energy relative reactivity relative electronegativity Ions charge on common ions Periodic table

Elements Sodium Na Periodic table What is the number and name of group? What is the principal energy level? What charge is on a sodium ion? Which is larger, a sodium atom or ion? Which is larger, a sodium atom or a chlorine atom? Which is larger, a sodium atom or a potassium atom? Which is more reactive, sodium or potassium? Which has greater electronegativity, sodium or fluorine?

Ions Periodic table What is the charge on ions formed from the group 2 alkaline earth metals? What is the charge on ions formed from the group 7 halogens? What is the charge on ions formed from group 6? Since compounds must have a neutral charge, what would be the formula for a compound formed when calcium and chlorine react? Write an equation for the reaction of calcium and chlorine?

Nomenclature Flowchart Ionic compounds (metal and nonmetal) Q Name CaBr 2 Q Name Fe 2 S 3 Q Name MgCO 3 Covalent compounds (nonmetals) Q Name SO 2 Q Name N 2 O 4 Acids Table 5.5 and 5.6 Q Name HCl (aq) Q Name H 2 SO 4(aq) Polyatomic ions Q Name PO 4 3- Q Hydroxide ion Nomenclature Nonmetal name with ide ending + 1 nonmetal Name the metal Single-Charge Metal 2 Nonmetals 1) Use Greek prefixes to indicate subscripts 2) second element ide ending *Metal + Nonmetal Name the polyatomic ion + 2 nonmetals Indicate metal charge by (Roman #) or Latin name (-ous or ic) Multiple-Charge Metal Chemical Formula H + Nonmetal(s) Name as acids * Treat NH 4 + as a metal when naming compounds

Chemical Bonding Filled shells are chemically stable Octet rule How atoms bond Electron dot formulas Lewis structures Not all e- participate in chem bonding Inner shells: core electrons Valence shell: outermost shell chem reactions and bonding Can be found whenever a noble gas element is reached on the periodic table Atoms form ions that have the same number of valence electrons as the outermost shell of noble gas element

Chemical Bonding Filled shells are chemically stable Octet rule How atoms bond Electron dot formulas Lewis structures Hydrogen and helium have shells filled with 2e- The first few periods of the tables have a maximum of 8 e- in the valence shell Groups I and II lose e- and become cations Groups VI and VII gain e- to become anions

Chemical Bonding Filled shells are chemically stable Octet rule How atoms bond Electron dot formulas Lewis structures Each atom acquires 8e- in their outer shell Transfer e-: ionic bond Example: potassium bromide KBr Potassium (metal) gives up 1e- K 1+ Bromine (nonmetal) takes 1 e- Br 1- Share e-: covalent bond Example: Hydrogen chloride HCl hydrogen has 1valence e- chlorine has 7 valence e- Hydrogen shares 1e- with chlorine Chlorine shares 1 e- with hydrogen

Chemical Bonding Filled shells are chemically stable Octet rule How atoms bond Electron dot formulas Lewis structures Number of dots represent number of valence electrons Hydrogen chloride H Cl e- have: 1 7 e- want 2 8 10e- minus 8e- = 2e- 2e-/2e- = 1 shared bond

Chemical Quantities Balanced equation Mole concept Percent composition Relative # of molecules of reactants and products C (s) + O 2(g) CO 2(g) Empirical formula Molecular formula

Chemical Quantities Balanced equation Mole concept Percent composition Empirical formula Molecular formula Mass of 1.00 mole element is equal to the atomic mass in grams 1.00 mole = 6.02 x 10 23 units Avogadro s number 1.00 moles of carbon atoms weighs 12.0 grams and has 6.02 x 10 23 atoms of C Equalities for carbon

Chemical Quantities Balanced equation Mole concept Percent composition Empirical formula Q How many moles are in 6.02 grams of carbon? Q How many atoms are in 2.00 moles of carbon? Molecular formula Q How many grams are in 2.00 moles of carbon?

Chemical Quantities Balanced equation Mole concept Percent composition Empirical formula Molecular formula Percent by mass of each element in a compound Percent = part in grams x 100% whole What is the percent of C in CO 2? 1C = 12.0 g = 12.0 g 2O = 16.0 x 2 = 32.0 g 44.0 g 12.0 g/ 44.0 g x 100% = 27.3%

Chemical Quantities Balanced equation Mole concept Percent composition Empirical formula Molecular formula Empirical formula is the simplest whole number ratio of the atoms in a molecule Molecular formula is a multiple of the empirical formula and along with the structure of the molecule, identifies the molecule.

Chemical Equations Balance an equation Diatomic molecules Correct formulas Same # of each type of atom on both sides of the equation Whole # coefficients Start with the most complex formula first Keep polyatomic ions together Q K (s) + H 2 O (l) H 2(g) + KOH (aq)

Chemical Equations Balance an equation Diatomic molecules Occur naturally H 2 O 2 N 2? Cl 2 Br 2 I 2 Q Which gas is missing?

Reactions Signs of a reaction Forces that drive a reaction Aqueous solutions Equations Molecular Complete Ionic Net ionic Solubility tables Classify reactions Activity series Gas Precipitate Perm. color change Q What is a 4 th sign that a reaction is taking place?

Reactions Signs of a reaction Forces that drive a reaction Aqueous solutions Equations Molecular Complete Ionic Net ionic Solubility tables Classify reactions Activity series When ionic compounds dissolve in water, the cations and anions separate from each other Ions are free to move Dissociation K 2 SO 4(aq) 2K + (aq) + SO 4 2- (aq) Website example

Reactions Signs of a reaction Forces that drive a reaction Aqueous solutions Equations Molecular Complete Ionic Net ionic Solubility tables Classify reactions Activity series Chemical reactions can be divided into five categories: Combination or Synthesis Decomposition Single-Replacement Double-Replacement Neutralization

Reactions Q: Match each reaction with its type A) BaCl 2 (aq) + K 2 CrO 4 (aq) BaCrO 4 (s) + 2 KCl(aq) B) H 2 SO 4 (aq) + 2 KOH(aq) K 2 SO 4 (aq) + 2 H 2 O(l) C) Fe(s) + CuSO 4 (aq) FeSO 4 (aq) + Cu(s) D) CaCO 3 (s) CaO(s) + CO 2 (g) E) 4 Fe(s) + 3 O 2 (g) 2 Fe 2 O 3 (s) Combination or Synthesis Decomposition Single-Replacement Double-Replacement Neutralization

Stoichiometry Balanced Equation Interpret #moles of reactants and products Calculate the mass of reactants and products Stoichiometry refers to the quantitative relationship between reactants and products in a chemical reaction. Limiting Reactants Which reactant limits how much product is formed Which reactant is in excess Percent Yield

Stoichiometry Balanced Equation Interpret #moles of reactants and products Calculate the mass of reactants and products Q. How many moles of oxygen gas react with 2.25 moles of magnesium to make magnesium oxide? 2 Mg (s) + O 2(g) 2 MgO (s) Limiting Reactants Which reactant limits how much product is formed Which reactant is in excess Percent Yield

Stoichiometry Balanced Equation Interpret #moles of reactants and products Calculate the mass of reactants and products Limiting Reactants Which reactant limits how much product is formed Which reactant is in excess Percent Yield Q. How many moles of oxygen gas react with 2.25 moles of magnesium to make magnesium oxide? 2 Mg (s) + O 2(g) 2 MgO (s) Q. How many grams of MgO are formed? Hint: find the molar mass of MgO Mg = 24.3 g/mole O = 16.0 g/mole MgO =

Stoichiometry Balanced Equation Interpret #moles of reactants and products Calculate the mass of reactants and products Limiting Reactants Which reactant limits how much product is formed Which reactant is in excess Q. How many moles of oxygen gas react with 2.25 moles of magnesium to make magnesium oxide? 2 Mg (s) + O 2(g) 2 MgO (s) Q. How many grams of MgO are formed? 90.7g Q. If only 45.4g of MgO form, what is the percent yield? Percent Yield = actual yield (g) x 100% theoretical yield (g)

Stoichiometry Balanced Equation Interpret #moles of reactants and products Calculate the mass of reactants and products Limiting Reactants Which reactant limits how much product is formed If 2 moles of H 2 and 2 moles of O 2 react, how many moles of water are formed? 2H 2 + O 2 2H 2 O Q. Which is the limiting reactant? H 2 or O 2 Which reactant is in excess Percent Yield

Properties of Gases What causes gas pressure What is absolute 0 What is vapor pressure How does volume affect pressure How does temperature affect pressure How do the number of molecules affect pressure

Chapter 4: Periodic table

Chem 101 Review. Fall 2012