ALEVEL化学.ppt

Ionic Compounds,This is Important!,On the Periodic Table remember where to:,and the nonmetals,find the metals,If You Dont Remember How to Tell Metals From Nonmetals,Nothing in This Chapter Will Make Sense!,Ionic Compounds,There are two types of ionic compounds Binary ionic compounds and Ionic compounds that contain“polyatomic ions”.,Binary Ionic Compounds,Type 1:Binary Ionic Compounds,1.“Binary”means 2(as in“bicycle”“2 wheels”)A binary ionic compound has only 2 elements:(example:BaCl2)The first element is always a metal!The second element is always a nonmetal!,Type 1:Binary Ionic Compounds,“2 elements”means just that“2 elements”!There can be more than one ion of an element!Example:AlF3 AlF3 contains only 2 elements:Al&F.AlF3 has 1 Al+3 ion,and 3 F-1 ions.metal(+)&nonmetal(-)The subscript tells you how many ions are in the compound(a“1”is understood and not written),Naming Binary Ionic Compounds,Naming Binary Ionic Compounds,To name a binary ionic compoundWrite the name of the metal ion(+)(this is just the name of the metal)Write the name of the nonmetal ion(-)(the nonmetal ion has the same“root”as the nonmetal,but with an“-ide”ending)”).Examples:“chlorine”becomes“chloride”“oxygen”becomes“oxide”“nitrogen”becomes,“nitride”,Thats It!,Just write the metal ion name first,then the nonmetal ion name second!(remember the“ide”nonmetal ending)Practice:(name these),K2SMgOSr3As2,potassium sulfidemagnesium oxidestrontium arsenide,Writing the Formula of a Binary Ionic Compound,Remember,metals are always(+)because they lose electrons,andNonmetals are always(-)because they gain electrons!In any ionic compound,the total(+)must EQUAL the total(-)!,Writing Binary Ionic Compounds,To write a binary ionic compound formulayou must know the charge of the metal ion and the nonmetal ion!There are two ways to know these Memorize them,or Look at the periodic table!Guess which is easier?!,You Guessed it!The“representative”elements are easy!,+1,+2,+3,Each family has its own charge!,-3,-2,-1,0,Noble gas“wannabes”,remember?,In Family 14,only Sn and Pb form ions,14,The transition metals do not follow any simple rules.(Many have two possible charges!)Some must be memorized,but,there IS an easy system for the others The Roman Numeral after the name gives you the(+)charge!Examples:“copper(I)”=Cu+1“iron(III)”=Fe+3“lead(IV)”=,Pb+4,There will be four metals we will study that have two different“oxidation numbers”,or charges(there are others!)Iron(Fe),Copper(Cu),Lead(Pb)and Tin(Sn)Iron:Fe+2 iron(II),or Fe+3 iron(III)Copper:Cu+1 copper(I),or Cu+2 copper(II)Lead:Pb+2 lead(II),or Pb+4 lead(IV)Tin:Sn+2 tin(II),or Sn+4 tin(IV),IONIC COMPOUNDS ARE NEUTRAL!Be sure the(+)charges=the(-)charges!Example:“aluminum fluoride”,aluminum ions are Al+3,fluoride ions are F-1,Al+3,F-1,AlF3,(Al+3+F-1+F-1+F-1),Adds up to zero!,The compound hasNO charge!,Practice:write the formula for:,Writing Binary Ionic Compounds,calcium fluoride,lithium phosphide,aluminum oxide,+2,-1,CaF2,+3,Al2O3,+1,-3,Li3P,-2,copper(II)chloride,CuCl2,Cu+2,and Cl-1,Ionic formulas are“formula units”of ionic compounds ionic compounds cant form molecules!Remember to reduce any ionic formula to a lowest ratio,Example:barium oxide,Ba+2,O-2,Ba2O2?,Reduce to“BaO”,Special Note:be SURE to write element symbols clearly!Lower and upper case letters must be obvious!,Compounds Containing Polyatomic Ions,Type 2:Ionic CompoundsContaining“Polyatomic Ions”,Polyatomic ions are GROUPS of atoms with a charge!(most will have a negative(-)charge,just like a non-metal ion)You will be given a list of these to use,“poly”means“many”,so“polyatomic”means“many atoms”!(These are ions made of groups of atoms)!,Polyatomic Ions,An example:the polyatomic ion,“nitrate”,-1,This group of atoms carries a charge of(-1).,Nitrates formula is:NO3-1,contains 1 nitrogen and 3 oxygen atoms!,Naming Compounds with Polyatomic ions,Naming Ionic Compounds With Polyatomic Ions,To name an ionic compound with polyatomic ions is really EASYWrite the name of the positive ion(+)(usually the name of the metal,but watch for Fe,Cu,Sn,and Pb Roman Numerals needed)Write the name of the negative ion(-)(usually the polyatomic ion)Thats IT!Example:Mg(NO3)2,“magnesium nitrate”,Practice naming ionic compounds containing polyatomic ions(get out your ion list),(NH4)2CO3K3PO4Zn(MnO4)2CuClO3Pb(OH)2,Ammonium carbonatePotassium phosphateZinc permanganateCopper(I)chlorateLead(II)hydroxide,Writing the Formula of a Compound That Contains Polyatomic Ions,To write a formula using polyatomic ions,you must know the formula and charge of the metal ion and the polyatomic ion.The metal ions you know(periodic table)you will get a list of polyatomic ions with their formulas and charges.,As in ALL ionic compounds,the total(+)must be equal to the total(-)!Just look at the charges,and make sure they add up to zero.,“sodium”=Na+1,“carbonate”=CO3-2,Na+1,CO3-2,“Na2CO3”,+Na+1,Na+1,+CO3-2,Adds up to zero!,Example:“sodium carbonate”,What if more than one polyatomic ion is needed?Wrap the polyatomic ion in parenthesis,then add the subscript.Example:“aluminum sulfate”,aluminum ions are Al+3,sulfate ions are SO4-2,Al+3,SO4-2,(Al+3+Al+3+,Adds up to zero!,SO4-2+SO4-2+SO4-2),2 Al+3,3 SO4-2,Al2(SO4)3,Practice writing the formula of ionic compounds containing polyatomic ins,NH4IAl(CN)3Sn(NO3)2Zn3(PO4)2Pb(SO4)2,Ammonium iodideAluminum cyanideTin(II)nitrateZinc phosphateLead(IV)sulfate,HYDRATES,Some ionic compounds“collect”water from the moisture in the air.They trap this“collected water”in their crystals.When they have trapped this water,they are called“hydrates”.Their formula includes water,written after a raised dot:,MgSO4 5H20,(magnesium sulfate pentahydrate),PrefixMonoDiTriTetraPentaHexaHeptaOctaNonaDeca,Number of H20s12345678910,Note:these prefixes will also be used when naming covalent compounds!,Write the name of the ionic compound,then write the prefix in front of the word“hydrate”.,Practice naming hydratesCaCl22H2OBa(OH)28H2OMgSO47H2ONaC2H3O23H2OFePO44H2O,Calcium chloride dihydrate Barium hydroxide octahydrate Magnesium sulfate heptahydrate Sodium acetate trihydrateIron(III)phosphate tetrahydrate,