Naming Compounds Day 2 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: Na1O2 Na2O • What is the formula of copper(II) oxide? Cu2O2 Cu2O2 CuO • For covalent compounds, simply use the prefixes to tell you the number of each element: • What is the formula for dinitrogen trioxide? N 2O 3 • Give formulae for: lithium sulfide, dinitrogen monoxide, lead(IV) sulfate Write and name the following covalent compounds (IUPAC) lithium sulfide Li1S2 Li2S dinitrogen monoxide N2O lead(IV) sulfate Pb4(SO4)2 Pb2(SO4)4 Pb(SO4)2 Assignment 1. Name each according to IUPAC rules: a) ZnS, b) FeCl3, c) CaCO3, d) P2O5, e) NaCN, f) N2F2, g) MgHPO4, h) Cu(BrO3)2, i) K2O, j) BF3 2. Give the valence of a) Fe in FeO, b) Mn in MnO2 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 Complete exercises on handout Steps: 1. Determine if its ionic or covalent 2. If ionic, determine if its metal has one or more valence 3. Name according to appropriate rules Answers – 1, 2 a) b) c) d) e) f) g) h) i) j) zinc sulfide iron(III) chloride calcium carbonate diphosporus pentoxide sodium cyanide dinitrogen difluoride magnesium hydrogen phosphate copper(II) bromate potassium oxide boron trifluoride 2 a) 2 b) 4 Answers – 3 a) Na2O h) Cl2O b) KI i) Ag2S c) PbS2 j) Mg3N2 d) Hg2O k) Al(ClO)3 e) FeO l) f) m) CaCrO4 Fe3(PO4)2 g) CuF2 IF5 n) P2S5 Naming Bases • Bases contain an OH group • C6H12O6 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 NH4+ at their beginning) • Bases are named like other ionic compounds: • +ve is named first, followed by the polyatomic ion - calcium hydroxide Ca(OH)2 - copper(I) hydroxide CuOH - Al(OH)3 aluminum hydroxide - NH4OH ammonium hydroxide Naming Acids: Binary acids • All acids start with H (e.g. HCl, H2SO4) • 2 acids types exist: binary acids and oxyacids Binary: H + non-metal. E.g. HCl Oxy: H + polyatomic ion. E.g. H2SO4 • 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 hydrogen bromide HI(aq) hydr(o)iodic acid HBr(s) chloride) H2S(aq)hydrosulfuric acid H2S(g) hydrogen sulfide Naming Acids: Oxyacids • 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. H2SO3 1) sulphite, 2) sulphous, 3) sulphurous, 4) sulphurous acid HNO2 hypochlorous acid H3PO4(aq) carbonic acid Naming Acids: Oxyacids • 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. H2SO3 1) sulphite, 2) sulphous, 3) sulphurous, 4) sulphurous acid HNO2 hypochlorous acid - nitrous acid - HClO H3PO4(aq) carbonic acid - phosphoric acid - H2CO3 Assignment: give formula or name a) chloric acid b) hydrosulfuric acid c) hydrobromic acid d) phosphorous acid e) iodic acid f) HCl(g) g) HCl(aq) h) H2SO4(s) i) H2SO4(aq) j) HClO2 k) HF(aq) a) HClO3 b) H2S(aq) c) HBr(aq) d) H3PO3 e) HIO3 f) hydrogen chloride g) hydrochloric acid h) sulfuric acid i) sulfuric acid j) chlorous acid k) hydrofluoric acid Hydrates For more lessons, visit www.chalkbored.com • Some compounds contain H2O in their structure. These compounds are called hydrates. • This is different from (aq) because the H2O is part of the molecule (not just surrounding it). • The H2O can usually be removed if heated. • A dot separates water: e.g. CuSO4•5H2O is copper(II) sulfate pentahydrate. • A greek prefix indicates the # of H2O groups. Na2SO4•10H2O sodium sulfate decahydrate nickel(II) sulfate hexahydrate NiSO4•6H2O sodium carbonate monohydrate Na2CO3•H2O BaCl2•2H2O barium chloride dihydrate