Ionic Bonds – Results from the complete transfer of electrons Results in a formation of two charged atoms called ions The atom that gains electrons becomes negatively charged and is called an anion The atom that loses electrons becomes positively charged and is called a cation NaCl example! Honors Notes The attraction of the positive and negative charges results in a very weak bond Covalent Bonds – Results from the sharing of electrons The shared electrons create a very strong bond These are the bonds that make molecules possible Ionic compounds result when metals react with nonmetals Metals lose electrons to match the number of valence electrons of their nearest noble gas Positive ions form when the number of electrons are less than the number of protons Group 1 metals → ion 1+ Group 2 metals → ion 2+ Group 13 metals → ion 3+ Between atoms of metals and nonmetals with very different electronegativity Bond formed by transfer of electrons Produce charged ions of all states, conductors, and have high melting point. Examples; NaCl, CaCl2, K2O 1 1). Ionic bond – electron from Na is transferred to Cl, this causes a charge imbalance in each atom. The Na becomes (Na+) and the Cl becomes (Cl-), charged particles or ions. Between nonmetallic elements of similar electronegativity. Formed by sharing electron pairs Stable non-ionizing particles, they are not conductors at any state Examples; O2, CO2, C2H6, H2O, SiC 2. Covalent bonds- Two atoms share one or more pairs of outer-shell electrons. Oxygen Atom Oxygen Atom We can predict which atoms will bond based on their oxidation numbers ◦ Ex 1: Na has a +1 Oxidation Number; it wants to lose one electron; Cl has a -1 Oxidation Number; it wants to gain one electron These atoms will react quickly and violently in a 1:1 ratio to give NaCl Oxygen Molecule (O2) 2 We can predict which atoms will bond based on their oxidation numbers What compound is formed when Ba reacts with Br? What compound is formed when Be reacts with O? What compound is formed when Al reacts with I? ◦ Ex 2: Ca has a +2 Oxidation Number; it wants to lose two electron; F has a -1 Oxidation Number; it wants to gain one electron ◦ BaBr2 Ca will give one of its valence electrons to one F and the second electron to a second F, giving CaF2 ◦ BeO ◦ AlI3 The metal will take its positive oxidation number and the non-metal will have to take its negative oxidation number. Example 1: Sodium reacts with oxygen to produce Na2O, what is the name of this compound ◦ Since there is only one possible compound, we do not have to indicate the number of elements ◦ Only one compound can be formed sodium oxide Name of Metal Root of ( NonNon-metal) -ide Example 2: What is the chemical formula for aluminum oxide ◦ First write the symbols of the elements ◦ Next write the oxidation number of each element above that element ◦ Switch the oxidation numbers and reduce What is the name of Mg3N2? What is the name of Li2Se? What is the formula for indium chloride? What is the formula for hafnium phosphide? ◦ magnesium nitride ◦ lithium selenide ◦ InCl3 ◦ Hf3P4 3 -2 Al O 3 The metal will take one of its positive oxidation numbers and the non-metal will have to take its negative oxidation number. ◦ First we need to determine how many electrons that iridium needs to lose in order to satisfy 6 bromine atoms. ◦ Since the metal has more than one possible oxidation number, multiple compounds can be formed ◦ We need a distinct name for each Name of Metal Oxidation State Root of ( Metal’s as a Roman Numeral) ( NonNon-metal) Example 1: What is the name of IrBr6? Each bromine needs one electron There is only one iridium in this compound Therefore, the iridium atom will have to supply all six electrons, giving it a +6 oxidation number. iridium(VI) bromide -ide Example 2: What is the formula for mercury(II) nitride? What is the name of RuN? ◦ First write the symbols of the elements ◦ Next write the oxidation number of each element above that element ◦ Switch the oxidation numbers and reduce What is the name of MnO3 What is the formula for paladium(IV) bromide? What is the formula for molybdenum(V) sulfide? ◦ ruthenium(III) nitride ◦ manganese(VI) oxide ◦ PdBr4 ◦ Mo2S5 2 -3 Hg N Polyatomic Ions – strongly bound group of atoms that have either lost or gained electrons and become charged. ◦ List of common Polyatomic Ions are on the back of your Periodic Table ◦ Polyatomic ions act as a single atom, with a single name ◦ Subscripts within the ion cannot be changed ◦ Since there is only one oxidation number for the metals and Polyatomic Ion, only one compound can be produced. Naming these compounds is just like rule 1, except we do not add –ide to the end of the polyatomic ion Name of Metal Name of ( Polyatomic Ion ) 4 What is the name of Mg(NO3)2 What is the formula for calcium iodite? ◦ First, since the second name does not end in –ide, a polyatomic ion is involved. ◦ Write the symbol for calcium and formula for iodite. ◦ Write the oxidation numbers above the metal and the polyatomic ion ◦ Switch the numbers, and use parenthesis around the polyatomic ion if necessary ◦ First, you should recognize that there are more than two elements involved, which means that a Polyatomic Ion is involved ◦ Next, look up the Metal in the periodic table and confirm that it has a single oxidation number ◦ Look up the name of the Polyatomic Ion magnesium nitrate What is the name of KHSO4? -1 Ca2(IO2) ◦ potassium hydrogen sulfate ◦ potassium bisulfate What is the name of In2(C2O4)3? ◦ We must use Roman Numerals to indicate which oxidation number the metal is using ◦ indium oxalate What is the formula of strontium bromate? What is the formula for germanium phosphate? When the metal has more than one possible oxidation number, more than one compound can be formed ◦ Sr(BrO3)2 Name of Metal Oxidation State Name of ( Metal’s as a Roman Numeral ) Polyatomic Ion ◦ Ge3(PO4)4 What is the name of RhMnO4? ◦ First, there are more than two elements involved ◦ Look up the oxidation and name of MnO4 It could be permanganate (-1) or manganate (-2) ◦ Finally, figure out which oxidation number the metal is using. If this is permanganate, rhodium would have to have a +1 oxidation number, this is not possible for rhodium. Therefore, this must be manganate, so rhodium would have to take its +2 oxidation number rhodium(II) manganate What is the formula for nickel(II) ferrocyanide? ◦ First, since the second name does not end in ide, a polyatomic ion is involved ◦ Write the symbol for nickel and formula for ferrocyanide ◦ Write the oxidation numbers above the metal and the polyatomic ion ◦ Switch the numbers, and use parenthesis around the polyatomic ion if necessary and reduce 2 -4 Ni 2(Fe(CN)6) 5 What is the name of Cr(IO)3? ◦ chromium(III) hypoiodite Since nonmetals have more than one oxidation number, there will always be more than one compound produced What is the name of CuMnO4? What is the formula for palladium(IV) ferricyanide? What is the formula for molybdenum(VI) dichormate? One – monomono- Five – penta penta-- Two – didi- Six – hexahexa- ◦ Mo(Cr2O7)3 Three – tri tri-- Seven – hepta hepta-- Four – tetra tetra-- Eight – octaocta- ◦ copper(II) manganate or copper(I) permanganate ◦ Therefore we have to have a distinct name for each compound ◦ To do this we use a prefix to indicate how many atoms of each element are present ◦ Pd3(Fe(CN)6)4 Using prefixes ◦ The prefix mono- is only used on the second element Ex: PF3 is named phosphorus trifluoride ◦ If two vowels are adjacent, leave them Ex: NI3 is named nitrogen triiodide ◦ In the case of monoxide only, drop one “o” Ex 1: What is the name of P2S3? Ex 2: What is the name of As7I3? Ex 3: What is the chemical formula of dihydrogen monoxide? Ex 4: What is the chemical formula of dinitrogen pentaoxide? ◦ diphosphorus trisulfide ◦ heptaarsenic triiodide ◦ H 2O ◦ N2O5 Acid – any compound that is capable of giving up a positive hydrogen ion (proton) ◦ Strength of acid depends on how easily the hydrogen ion is released ◦ Anytime a compound starts with H, the compound is typically an acid Water (H2O) and hydrogen peroxide (H2O2) are noteworthy exceptions Ex 1: What is the name of HCl? ◦ Since the compound starts with H, it is probably an acid. ◦ Use the prefix hydro-, the suffix -ic, and the word acid hydrochloric acid Root of -ic acid ( NonNon-metal) Hydro-Hydro 6 What is the name of HAt? ◦ hydroastatic acid Identifying Polyatomic Acids ◦ Formula will start with H ◦ Has three or more elements What is the name of HBr? What is the formula for hydroiodic acid? What is the formula for hydrofluoric acid? ◦ hydrobromic acid ◦ HI Naming depends on the ending of the Polyatomic Ion ◦ Ions ending in -ate or -ide Root of -ic ( Polyatomic Ion) ◦ HF acid ◦ Ions ending in -ite Root of Polyatomic Ion ( Ex 1: What is the name of H3PO4? ◦ First, notice that since the compound starts with H, we are dealing with an acid acid Ex 2: What is the name of H3PO3? ◦ First, notice that since the compound starts with H, we are dealing with an acid Also, there are more than two elements; we should think polyatomic ion ) -ous Also, there are more than two elements; we should think polyatomic ion ◦ Next, look up the name of the polyatomic ion ◦ Since phosphate ends in -ate, change the suffix to -ic and add the word “acid.” ◦ Next, look up the name of the polyatomic ion ◦ Since phosphite ends in -ite, change the suffix to ous and add the word “acid.” phosphoric acid phosphorous acid Ex 3: What is the formula for aluminic acid? What is the formula for manganic acid? ◦ Since there is no hydro prefix, we know that this must be a polyatomic acid. ◦ Next, the -ic ending means that the ion must really end in -ate What is the formula for sulfurous acid? What is the name of HNO2? What is the name of HNO3? We must be looking of the aluminate ion ◦ Because this is an acid, hydrogen will be involved ◦ Write the symbols and oxidation numbers, switch the oxidation numbers, and reduce. 1 ◦ H2MnO4 ◦ H2SO3 ◦ nitrous acid ◦ nitric acid -3 H AlO3 7