Chemical Compounds_p4.notebook October 25, 2016

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1 Chemical Reactins we already knw chemical reactins invlve electrns when elements frm cmpunds, changes ccur in the arrangement f electrns atms want t have a cmplete valence shell (like the nble gases) they achieve this by sharing r transferring electrns Why are nble gases stable? they have full uter rbits w can we give lithium a full uter shell? 1) Add 7 electrns t the uter shell. 2) Remve 1 electrn frm the uter shell. Which is easier? What wuld the atm lk like after lsing that electrn? Prtns +3 Electrns 2 1+ Charge +1 The atm nw has a charge and is called an in. We write the charge as a superscript t the right f the symbl. Bhr Diagram Questins 1. What part f the atm is invlved in making chemical bnds? 2. Fr the metallic elements sdium, magnesium, and aluminum, answer the fllwing questins: a) Draw a Bhr diagram fr each element. w many electrns are in their uter rbits? b) D these metallic elements tend t gain r lse electrns? Give reasns fr yur answer. c) What is the charge n each f the metal ins? (Include the in symbl.) 3. Fr the nnmetallic elements nitrgen, xygen, and flurine, answer the fllwing questins: a) Draw a Bhr diagram fr each element. w many electrns are in their uter rbits? b) D these nnmetallic elements tend t gain r lse electrns? Give reasns fr yur answer. c) What is the charge n each f the nnmetal ins? (Include the in symbl.) 4. Predict the names and charges f the ins that cesium, barium, and brmine might frm. 2+ Prtns +20 Electrns 18 Charge +2 Metals tend t lse electrns t frm psitive ins. 5. Beryllium and flurine react t frm an inic cmpund. a) Which element is the metal and which is the nnmetal? b) Draw Bhr diagrams f beryllium and flurine. c) w many electrns must each element gain r lse t frm stable ins? d) Draw sketches t shw hw this cmpund frms by transfer f electrns. e) Indicate the inic charges n the ins. f) What is the verall charge n the cmpund? g) What is the chemical frmula f the cmpund? 6. Repeat questin 2 fr the cmpund frmed by aluminum and flurine. 7. a) w d metals frm inic cmpunds with nnmetals? b) Describe the prcess with an example. 2 Prtns +16 Electrns 18 Charge 2 Nnmetals tend t gain electrns t frm negative ins. We change their name t end in " ide" Try these: Atm In Flurine Brmine xygen Chemical Cmpunds We will learn abut tw types f cmpunds: Inic Electrns are transferred between metals and nnmetals Mlecular Electrns are shared between nnmetals. Let's try sme examples. Cmpund Fe2 KF C2 NaCl 2 Mlecular r inic inic inic mlecular inic mlecular A chemical frmula is a cmbinatin f symbls that represent a particular cmpund. It shws us what elements are in the cmpund the number f each atm present Cmpund # Element # Element Fe2 1 irn 2 xygen KF 1 ptassium 1 flurine C2 1 carbn 2 xygen NaCl 1 sdium 1 chlride 2 2 hydrgen 1 xygen

2 w d inic cmpunds frm? Resulting inic cmpund? frmed by a metal in and a nnmetal in Charge Element? n in? the metal in lses electrns t frm a psitive catin the nnmetal gains electrns t becme a negative anin\ the ppsite charges cause the tw ins t be attracted t each ther this attractin is called an inic bnd the result is an electrically neutral cmpund Let's lk at sme examples. + Li F +1 1 LiF Writing the fr Inic Cmpunds 1. Temprarily write the inic charge abve each symbl. 2. Crisscrss the inic charges, using them as subscripts fr the ppsite ins. 3. Reduce the subscripts t the lwest numbers pssible. Let's try sme examples. What cmpund is frmed frm sdium and brmine? 1+ 1 Na Br Na 1Br 1 NaBr 2+ 1 Ca I CaI 2 we w dn't include yu feel the abut subscript thse nes? "1" What cmpund is frmed frm calcium and idine? What cmpund is frmed frm aluminum and sulfur? 3+ 2 Al S w d we name these cmpunds? Write the name f the metal fllwed by the name f the nnmetal ending in ide NaCl sdium chlride CaF 2 calcium fluride K 2 ptassium xide Al 2S 3 What cmpund is frmed frm nickel and xygen? 2+ 2 Ni Ni 2 2 Ni w we have d yu t feel reduce abut the thse subscripts tws? What cmpund is frmed frm tin and xygen? Sn Sn 2 4 Sn 2 we have t reduce the subscripts w d yu feel abut the tw and fur? n spaces between symbls in the chemical frmula the first Things letter f t remember! a chemical symbl is always capitalized. If there is a secnd letter, it is always lwercase.

3 Try this ne: Practice! Elements ptassium and xygen sdium and sulfur aluminum and idine silver and sulfur calcium and nitrgen Give the name and chemical frmula fr each f the fllwing: a) lithium and flurine b) calcium and brmine c) sdium and nitrgen d) aluminum and nitrgen e) sdium and idine f) beryllium and flurine lithium fluride (LiF) calcium brmide (CaBr 2) sdium nitride (Na 3N) aluminum nitride (AlN) sdium idide (NaI) beryllium fluride (BeF 2) Write the frmula fr the cmpund frmed by irn and idine. Naming cmpunds f plyvalent metals Sme metals can frm mre than ne kind f in they are called plyvalent metals. write the name f the metal add a Rman numeral in parentheses after it t indicate its inic charge use the "ide" ending fr the nnmetal 53 I 1 idide??? 1 Fe I??? 3+ 1 FeI 3 irn (III) idide Number 1 I 2 II 3 III 4 IV 5 V Rman numeral g) magnesium and xygen magnesium xide (Mg) h) gallium and sulfur gallium sulfide (Ga 2S 3) Try this ne: Fe 3N 2 irn (II) nitride Mre practice. 1. Write the frmula fr each f the fllwing cmpunds: a) cpper(i) brmide CuBr b) cpper(ii) brmide CuBr 2 FeS c) irn(ii) sulfide Plyatmic in: atms that tend t stay tgether and carry an verall inic charge (e.g., Nitrate in: N 3 ). 2. Write the name fr each f the fllwing cmpunds: a) SnCl 2 tin(ii) chlride b) SnCl 4 tin(iv) chlride c) PbBr 2 lead(ii) brmide 3. Write the frmula and name f the cmpund frmed by each f the fllwing cmbinatins f ins. a) Fe 3+ and 2 irn(iii) xide Fe 2 3 b) Ca 2+ and F c) Cu + and S 2 calcium fluride CaF 2 cpper(i) sulfide Cu 2S

4 Naming Cmpunds f Plyatmic Ins Ins that cntain mre than ne atm are called plyatmic ins. write the symbls fr the metal and the plyatmic in write the inic charges abve the symbls and crisscrss them write the name f the metal first, then the plyatmic in Try these: 3+ 1 a) Fe(N 3) Na S 4 Na 2S 4 sdium sulfate 2+ 1 Ba N 3 Ba(N 3) 2 barium nitrate irn (III) nitrate b) Pb(S 4) 2 lead (IV) sulfate 1+ 2 c) K 2C 3 ptassium carbnate d) ptassium hydrxide 1+ 1 K K w d nt d reduce yu feel the abut subscripts the 2 and within 4? the in because they are a grup use brackets w d arund we crisscrss the in if with yu a need plyatmic? mre than ne Ca(S 4) Al() 1. Write the frmulas fr the fllwing cmpunds: (a) sdium phsphate Na 3(P 4) Na + (P 4) 3 (b) calcium sulfate Ca 2+ (S 4) 2 (c) ptassium chlrate K(Cl 3) K + Cl (d) aluminum hydrxide Al 3+ (e) beryllium nitrate Be(N 3) 2 Be 2+ N (f) magnesium hydrgen carbnate Mg(C 3) 2 Mg 2+ C (g) nickel carbnate NiC 3 Ni 2+ C 2 2. Write the names fr the fllwing cmpunds: a) K 2C 3 b) Na 2S 4 c) Al(C 3) 2 d) AgN 3 ptassium carbnate sdium sulfate aluminum hydrgen carbnate silver nitrate e) lead(iv) carbnate Pb C 3 Pb 2(C 3) 4 Pb(C3) 2 w we d can yu reduce feel the abut subscript the 2 and 4? fr the whle grup Mlecular Cmpunds mst cmmn cmpunds d nt cntain ins they cntain neutral grups f atms called mlecules. a mlecule (r mlecular cmpund is made f nnmetals that are sharing electrns the shared electrns frm a cvalent bnd w many electrns des need? w many electrns des need? Diatmic Mlecules are elements that exist naturally as mlecules made f tw atms. 2, N 2, 2, F 2, Cl 2, Br 2, I 2 Start Geez! at 7, make w a can 7, and I remember dn t frget thse? the hat!

5 The cmbining capacity (r valency) is the number f cvalent bnds that a nnmetal needs t frm a stable mlecule. Cmbining 3 capacity? Cmbining 2 capacity? w can yu knw the cmbining capacity f an element? it's the number f grups away frm a nble gas. e.g., What cmpund is frmed frm carbn and hydrgen? Step 1: Write the left mst element first then the right C Element Step 2: Write the cmbining capacities abve the element symbls Step 3: Crisscrss the cmbining capacities t get subscripts Step 4: Reduce the subscripts if pssible Step 5: Remve any "1" subscripts they're nt needed 4 1 C C 1 4 C 1 4 C F Cl S Cmbining capacity Prefixes indicate the number f atms present. If there is nly ne atm f the first element listed, the prefix MN is nt needed. Number Prefix C 4 1. w can yu tell the difference between inic cmpunds and mlecular cmpunds? 2. a) What kinds f atms frm mlecular cmpunds? b) w d the atms in mlecular cmpunds frm stable electrn cnfiguratins? c) What type f bnd hlds atms tgether in mlecules? 3. the fllwing cmpunds: a) CBr4 carbn tetrabrmide b) NI3 c) F2 d) SiCl4 nitrgen triidide xygen difluride silicn tetrachlride 4. Write chemical frmulas fr and name the mlecular cmpunds frms by the fllwing pairs f elements: a) silin & xygen b) nitrgen & hydrgen c) phsphrus & chlrine d) sulfur & brmine e) xygen & flurine f) carbn & chlrine Inic Cmpunds NAMING Acids frm when hydrgen atms cmbine with certain ins The hydrgen in has an inic charge f 1+ ( + ). Acids have the subscript aq (aqueus) after their frmula. T name acids, fllw these simple guidelines: + ate = ic acid 2S 4 = sulfuric acid + ite = us acid 2S 3 = sulfurus acid + element = hydr ic acid Cl = hydrchlric acid An xyacid is simply and acid frmed when + cmbines with plyatmic ins that cntain xygen.