Nomenclature

We can determine the formula of a compound by completing Lewis diagrams or via the criss cross method By knowing the valence of elements you can determine the formula of compounds E.g. what compound would form from Ca + S? Step 1 - write valences: Ca 2+ S 2- Step 2 - cross down valences: Ca 2 S 2 Step 3 – reduce:CaS a) Al,Br b) K,S c) Zn,O d) Mg,N e) C,Cl f) Cu,O AlBr 3 K2SK2SZnOMg 3 N 2 CCl 4 CuO or Cu 2 O

Ionic compounds Rules for naming Names end in -ide. Example: sodium chloride Metal (cation) comes 1st (not chlorine sodide) Do not capitalize (unless it’s the start of a sentence) Give formulae & name: Ca + I, O + Mg, Na + S = Ca 2 I 1 = CaI 2 = calcium iodide = Mg 2 O 2 = MgO = magnesium oxide = Na 1 S 2 = Na 2 S = sodium sulfide

Multiple valence: Latin naming When the metal in an ionic compound is multivalent there are 2 methods: Latin or IUPAC As before, the name ends in -ide & metal is first The metal is named with it’s Latin or English root and ends in -ic or –ous to denote valence E.g. Cu 1 is cuprous, E.g. Cu 2 is cupric Lower = ous, Higher = ic Give formulas and Latin names for: Cu 2+ + Cl - = CuCl 2 = cupric chloride = copper (II) chloride (IUPAC) Cu + + Cl = CuCl = cuprous chloride = copper (I) chloride

Name ends in -ide, positive/metal comes first The valence of the metal is indicated in brackets using roman numerals E.g. Cu 1 is copper(I), Cu 2 is copper(II) Numbers refer to valences not to #s of atoms Try: Cu 2 +Cl, Zn 2 + Cl, Co 2 +Cl, Hg+S (do both) Cu 2 +Cl = Cu 2 Cl 1 = CuCl 2 = copper(II) chloride Zn 2 +Cl = Zn 2 Cl 1 = ZnCl 2 = zinc chloride Co 2 +Cl = Co 2 Cl 1 = CoCl 2 = cobalt(II) chloride Hg+S = Hg 1 S 2 = Hg 2 S = mercury(I) sulfide Hg+S = Hg 2 S 2 = HgS = mercury(II) sulfide Multiple valence: IUPAC naming

Groups of atoms can also have valences “Polyatomic ions” are groups of atoms that interact as a single unit. E.g. OH 1, (SO 4 ) 2. Ba 3 (PO 4 ) 2 = Compounds containing polyatomic ions So far we have given valences to single atoms Li + O Li 1 O 2  Li 2 O barium phosphate Naming compounds with polyatomic ions is similar to naming other ionic compounds You should note that compounds with polyatomic ions have names ending in -ate or -ite not -ide Note that most are negative, except ammonium Name: Ca(OH) 2, CuSO 4, NH 4 NO 3, Co 2 (CO 3 ) 3

- calcium hydroxide - copper(II) sulfate - ammonium nitrate - cobalt(III) carbonate Ca(OH) 2 CuSO 4 NH 4 NO 3 Co 2 (CO 3 ) 3 Compounds containing polyatomic ions

Naming covalent compounds -ide ending, each element has “prefix” 1mono 2di 3tri 4tetra 5penta 6hexa 7hepta 8octa 9nona 10deca prefix refers to # of atoms - not valence N 2 O 4 = dinitrogen tetroxide Exception: drop mono for first element CO 2 = carbon dioxide The first vowel is often dropped to avoid the combination of “ao” or “oo”. CO = carbon monoxide (monooxide) SO 2 = sulfur dioxide (doxide) Name: CCl 4, P 2 O 3, IF 7 P 4 O 10 = tetraphosphorus decoxide

Write and name the following covalent compounds (IUPAC) carbon tetrachloride diphosporus trioxide iodine heptafluoride CCl 4 P 2 O 3 IF 7

Working backwards: name to formula It’s possible to determine a formula from a name E.g. What is the formula of sodium oxide? To get the answer, first write the valences: Na 1 O 2  Na 2 O What is the formula of copper(II) oxide? Cu 2 O 2  Cu 2 O 2  CuO For covalent compounds, simply use the prefixes to tell you the number of each element: What is the formula for dinitrogen trioxide? N2O3N2O3 Give formulae for: lithium sulfide, dinitrogen monoxide, lead(IV) sulfate

Write and name the following covalent compounds (IUPAC) Li 1 S 2  Li 2 S N 2 O Pb 4 (SO 4 ) 2  Pb 2 (SO 4 ) 4  Pb(SO 4 ) 2 lithium sulfide dinitrogen monoxide lead(IV) sulfate

1.Name each according to IUPAC rules: a) ZnS, b) FeCl 3, c) CaCO 3, d) P 2 O 5, e) NaCN, f) N 2 F 2, g) MgHPO 4, h) Cu(BrO 3 ) 2, i) K 2 O, j) BF 3 2.Give the valence of a) Fe in FeO, b) Mn in MnO 2 3. Write formulas for: a) sodium oxide, b) potassium iodide, c) plumbic sulfide, d) mercury(I) oxide, e) ferrous oxide, f) iron(II) phosphate, g) copper(II) fluoride, h) dichlorine monoxide, i) silver sulfide, j) magnesium nitride, k) aluminum hypochlorite, l) iodine pentafluoride, m) calcium chromate, n) diphosphorus pentasulfide Assignment

Answers – 1, 2 a)zinc sulfide b)iron(III) chloride c)calcium carbonate d)diphosporus pentoxide e)sodium cyanide f)dinitrogen difluoride g)magnesium hydrogen phosphate h)copper(II) bromate i)potassium oxide j)boron trifluoride 2 a) 2b) 4

Answers – 3 a)Na 2 O b)KI c)PbS 2 d)Hg 2 O e)FeO f)Fe 3 (PO 4 ) 2 g)CuF 2 h)Cl 2 O i)Ag 2 S j)Mg 3 N 2 k)Al(ClO) 3 l)IF 5 m)CaCrO 4 n)P 2 S 5

Bases contain an OH group C 6 H 12 O 6 does not have an OH group If an OH group is present it will be clearly indicated: e.g. NaOH, Ca(OH) 2 Also notice that bases have a metal (or positive ion such as NH 4 + at their beginning) Bases are named like other ionic compounds: +ve is named first, followed by the polyatomic ion Naming Bases - calcium hydroxide - copper(I) hydroxide - Al(OH) 3 - NH 4 OH Ca(OH) 2 CuOH aluminum hydroxide ammonium hydroxide

All acids start with H (e.g. HCl, H 2 SO 4 ) 2 acids types exist: binary acids and oxyacids Binary: H + non-metal. E.g. HCl Oxy: H + polyatomic ion. E.g. H 2 SO 4 Each have different naming rules. Binary acids: naming depends on state of acid If it’s not aqueous: hydrogen + non-metal HCl(g) = hydrogen chloride If it is aqueous: hydro + non-metal + ic acid HCl(aq) = hydrochloric acid (aqueous hydrogen chloride) Naming Acids: Binary acids HBr(s) HI(aq) H 2 S(aq) H 2 S(g) hydrogen bromidehydroiodic acid hydrogen sulfidehydrosulfuric acid

Naming does not depend on the state (aq) 1) name the polyatomic ion 2) replace ate with ic, ite with ous 3) change non-metal root for pronunciation 4) add “acid” to the name E.g. H 2 SO 3 Naming Acids: Oxyacids HNO 2 hypochlorous acid H 3 PO 4 (aq) carbonic acid 1) sulphite,2) sulphous, 3) sulphurous, 4) sulphurous acid

Naming Acids: Oxyacids HNO 2 hypochlorous acid H 3 PO 4 (aq) carbonic acid - nitrous acid- HClO - phosphoric acid- H 2 CO 3

a) chloric acid b) hydrosulfuric acid c) hydrobromic acid d) phosphorous acid e) iodic acid f) HCl(g) g) HCl(aq) h) H 2 SO 4 (s) i) H 2 SO 4 (aq) j) HClO 2 k) HF(aq) Assignment: give formula or name a) HClO 3 b) H 2 S(aq) c) HBr(aq) d) H 3 PO 3 e) HIO 3 f) hydrogen chloride g) hydrochloric acid h) sulfuric acid i) sulfuric acid j) chlorous acid k) hydrofluoric acid

Some compounds contain H 2 O in their structure. These compounds are called hydrates. This is different from (aq) because the H 2 O is part of the molecule (not just surrounding it). The H 2 O can usually be removed if heated. A dot separates water: e.g. CuSO 4 5H 2 O is copper(II) sulfate pentahydrate. A greek prefix indicates the # of H 2 O groups. Hydrates sodium sulfate decahydrate nickel(II) sulfate hexahydrate Na 2 CO 3 H 2 O BaCl 2 2H 2 O Na 2 SO 4 10H 2 O NiSO 4 6H 2 O sodium carbonate monohydrate barium chloride dihydrate