Unit 5: Bonding and Inorganic Nomenclature

Transcription

1 Unit 5: Bnding and Inrganic Nmenclature Chemical Bnding Inic Bnds: atms give up r gain e and are attracted t each ther by culmbic attractin Na lses an e Cl gains an e Na Na 1+ + e Cl + e Cl inic cmpunds = salts Na 1+ + Cl NaCl K 1+ + NO 3 KNO 3 where NO 3 is a plyatmic in: a charged grup f atms that stay tgether Prperties f Salts 1. very hard each in is bnded t several ppsitely-charged ins 2. high melting pints many bnds must be brken 3. brittle with sufficient frce, like atms are brught net t each ther and repel

2 Cvalent Bnds atms share e t get a full valence shell C 1s 2 2s 2 2p 2 (4 v.e ) F 1s 2 2s 2 2p 5 (7 v.e ) bth need 8 v.e fr a full uter shell (ctet rule) Lewis structure: a mdel f a cvalent mlecule that shws all f the valence e 1. Tw shared e make a single cvalent bnd, fur make a duble bnd, etc. 2. unshared pairs: pairs f unbnded valence e 3. Each atm needs a full uter shell, i.e., 8 e. Eceptin: needs 2 e carbn tetrafluride (CF 4 ) C F F F C F F F F C F F

3 methane (C 4 ) C nitrgen triidide (NI 3 ) C C N I I N I I I N I I carbn diide (CO 2 ) C O O C O O = C = O cvalent cmpunds = mlecular cmpunds -- have lwer melting pints than d inic cmpunds Metallic Bnds In metals, valence shells f atms verlap, s v.e are free t travel between atms thrugh material Prperties f Metals cnduct heat and electricity; ductile; malleable Other Types f Bnds diple-diple frces, hydrgen bnds, Lndn dispersin frces; & in-diple frces (slutins)

4 Writing Frmulas f Inic Cmpunds chemical frmula: has neutral charge; shws types f atms and hw many f each T write an inic cmpund s frmula, we need: 1. the tw types f ins 2. the charge n each in Na 1+ and F NaF Ba 2+ and O 2 BaO Na 1+ and O 2 Na 2 O Ba 2+ and F BaF 2 criss-crss rule: charge n catin / anin becmes subscript f anin / catin ** Warning: Reduce t lwest terms. Al 3+ and O 2 Ba 2+ and S 2 In 3+ and Br Al 2 O 3 Ba 2 S 2 In 1 Br 3 Al 2 O 3 BaS InBr 3

5 Writing Frmulas w /Plyatmic Ins Parentheses are required nly when yu need mre than ne bunch f a particular plyatmic in. Ba 2+ and SO 4 2 BaSO 4 Mg 2+ and NO 2 Mg(NO 2 ) 2 N 4 1+ and ClO 3 N 4 ClO 3 Sn 4+ and SO 4 2 Sn(SO 4 ) 2 Fe 3+ and Cr 2 O 7 2 Fe 2 (Cr 2 O 7 ) 3 N 4 1+ and N 3 (N 4 ) 3 N

6 Inrganic Nmenclature Inic Cmpunds (catin/anin cmbs) Single-Charge Catins with Elemental Anins The single-charge catins are: grups 1, 2, 13, and Ag 1+ and Zn 2+ A. T name, given the frmula: 1. Use name f catin. 2. Use name f anin (it has the ending ide ). NaF sdium fluride BaO barium ide Na 2 O sdium ide BaF 2 barium fluride B. T write frmula, given the name: 1. Write symbls fr the tw types f ins. 2. Balance charges t write frmula. silver sulfide Ag 1+ S 2 Ag 2 S zinc phsphide Zn 2+ P 3 Zn 3 P 2 calcium idide Ca 2+ I CaI 2

7 Multiple-Charge Catins with Elemental Anins The multiple-charge catins are: Pb 2+ /Pb 4+, Sn 2+ /Sn 4+, transitin elements (nt Ag r Zn) A. T name, given the frmula: 1. Figure ut charge n catin. 2. Write name f catin. 3. Write Rman numerals in ( ) t shw catin s charge. 4. Write name f anin. FeO Fe? O 2 irn (II) ide Fe 2 O 3 2 Fe? 3 O 2 irn (III) ide Stck System f nmenclature CuBr Cu? Br cpper (I) brmide CuBr 2 Cu? 2 Br cpper (II) brmide B. T find the frmula, given the name: 1. Write symbls fr the tw types f ins. 2. Balance charges t write frmula. cbalt (III) chlride C 3+ Cl CCl 3 tin (IV) ide Sn 4+ O 2 SnO 2 tin (II) ide Sn 2+ O 2 SnO

8 Traditinal System f Nmenclature used histrically (and still sme tday) t name cmpunds w /multiple-charge catins T use: 1. Use Latin rt f catin. 2. Use -ic ending fr higher charge; -us lwer 3. Then say name f anin, as usual. Element Latin rt -ic -us gld, Au aur- Au 3+ Au 1+ lead, Pb plumb- Pb 4+ Pb 2+ tin, Sn stann- Sn 4+ Sn 2+ cpper, Cu cupr- Cu 2+ Cu 1+ irn, Fe ferr- Fe 3+ Fe 2+ Write frmulas: Write names: cuprus sulfide Pb 3 P 4 3 Pb? 4 P 3 Cu 1+ S 2 Cu 2 S plumbic phsphide auric nitride Pb 3 P 2 3 Pb? 2 P 3 Au 3+ N 3 AuN plumbus phsphide ferrus fluride SnCl 4 Sn? 4 Cl Fe 2+ F FeF 2 stannic chlride

9 Cmpunds Cntaining Plyatmic Ins Insert name f in where it shuld g in the cmpund s name. Write frmulas: irn (III) nitrite Fe 3+ NO 3 Fe(NO 3 ) 3 ammnium phsphide N 4 1+ P 3 (N 4 ) 3 P ammnium chlrite N 4 1+ ClO 2 zinc phsphate Zn 2+ PO 4 3 lead (II) permanganate Pb 2+ MnO 4 N 4 ClO 2 Zn 3 (PO 4 ) 2 Pb(MnO 4 ) 2 Write names: (N 4 ) 2 S 2 O 3 AgBrO 3 (N 4 ) 3 N ammnium thisulfate silver brmate ammnium nitride U(CrO 4 ) 3 U? 3 CrO 4 2 uranium (VI) chrmate Cr 2 (SO 3 ) 3 2 Cr? 3 SO 3 2 chrmium (III) sulfite

10 Cvalent Cmpunds -- cntain tw types f nnmetals Key: FORGET CARGES What t d: Use Greek prefies t indicate hw many atms f each element, but dn t use mn n first element. 1 mn 6 hea 2 di 7 hepta 3 tri 8 cta 4 tetra 9 nna 5 penta 10 deca EXAMPLES: carbn diide CO 2 CO carbn mnide dinitrgen triide N 2 O 3 N 2 O 5 dinitrgen pentide carbn tetrachlride CCl 4 NI 3 nitrgen triidide

11 Acid Nmenclature binary acids: acids w / and ne ther element Binary Acid Nmenclature 1. Write hydr. 2. Write prefi f the ther element, fllwed by -ic acid. F hydrfluric acid Cl hydrchlric acid Br hydrbrmic acid hydridic acid I hydrsulfuric acid 2 S yacids: acids cntaining, O, and ne ther element Cmmn yanins (plyatmic ins that cntain ygen) that cmbine with t make yacids: BrO 3 NO 3 2 CO 3 3 PO 4 ClO 3 2 SO 4 IO 3

12 Oyacid Nmenclature Write prefi f yanin, fllwed by -ic acid. BrO 3 brmic acid ClO 3 chlric acid 2 CO 3 carbnic acid sulfuric acid 2 SO 4 phsphric acid 3 PO 4 Abve eamples shw mst cmmn frms f the yacids. If an yacid differs frm the abve by the # f O atms, the name changes are as fllws: ne mre O = per ic acid mst cmmn # f O = ic acid ne less O = us acid tw fewer O = hyp us acid ClO 4 perchlric acid ClO 3 chlric acid ClO 2 chlrus acid ClO hypchlrus acid phsphrus acid 3 PO 3 hypbrmus acid BrO persulfuric acid 2 SO 5

13 Empirical Frmula and Mlecular Frmula lwest-terms frmula shws the true number and type f atms in a mlecule Cmpund Mlecular Frmula Empirical Frmula glucse C 6 12 O 6 C 2 O prpane C 3 8 C 3 8 butane C 4 10 C 2 5 naphthalene C 10 8 C 5 4 sucrse C O 11 C O 11 ctane C 8 18 C 4 9