CHEMLEC3 s Overview of the types of Ionic Compounds and Nomenclature (1).pdf

Overview of the Types of Ionic Compounds and Nomenclature CHAPTER III ARTS AND SCIENCES DEPARTMENT LEARNING OBJECTIVES After studying this chapter, you should be able to: ❏ Discuss the different types of ionic compounds and its properties ❏ Writing Formulas of the different types of ioni...

Overview of the Types of Ionic Compounds and Nomenclature CHAPTER III ARTS AND SCIENCES DEPARTMENT LEARNING OBJECTIVES After studying this chapter, you should be able to: ❏ Discuss the different types of ionic compounds and its properties ❏ Writing Formulas of the different types of ionic Compounds ❏ Naming Ionic and covalent compounds ❏ Name various ionic compounds Conceptual Definition of Acids and Bases Arrhenius Acid–Base Theory Arrhenius Acid ❑ Acids can be recognized because their chemical formulas have an “H” at the beginning, like HBr and HNO3. ❑ A hydrogen-containing compound that produces, in water, hydrogen ions (H+ ions). ❑ Hydrogen ions (the acidic species) are produced through ionization (the process whereby, in aqueous solution, positive and negative ions are produced from a molecular compound. ❑ Two common examples of Arrhenius acids are HNO3 (nitric acid) and HCl (hydrochloric acid). Conceptual Definition of Acids and Bases Arrhenius Acid–Base Theory Arrhenius Base ❑ Bases are easy to recognize because their chemical formulas end with “OH,” like NaOH or KOH. ❑ A hydroxide-containing compound that produces, in water, hydroxide ions (OH- ions) ❑ Hydroxide ions (the basic species) are produced through dissociation (the process whereby, in aqueous solution, positive and negative ions are released from an ionic compound. ❑ Two common examples of Arrhenius bases are NaOH (sodium hydroxide) and KOH (potassium hydroxide). Conceptual Definition of Acids and Bases Arrhenius Acid–Base Theory Copyright 2016 Cengage Learning Figure 10-1 The difference between the aqueous solution processes of ionization(Arrhenius acids) and dissociation (Arrhenius bases). Conceptual Definition of Acids and Bases Bronsted–Lowry Acid–Base Theory Bronsted-Lowry Acid ❑ A substance that can donate a proton (H+ ion) to some other substance. ❑ A proton donor. Bronsted-Lowry Base ❑ A substance that can accept a proton (H+ ion) from some other substance. ❑ A proton acceptor. Example When gaseous hydrogen chloride dissolves in water, it forms hydrochloric acid. This is a simple Bronsted–Lowry acid–base reaction. The chemical equation for this process is Conceptual Definition of Acids and Bases Bronsted–Lowry Acid–Base Theory Example The white solid haze that often covers glassware in a chemistry laboratory results from the gas-phase reaction between HCl and NH3: Note: Bronsted-Lowry acid and Bronsted-Lowry base production must occur simultaneously. You cannot have one without the other. Conceptual Definition of Acids and Bases Bronsted–Lowry Acid–Base Theory ❑ An amphiprotic substance is a substance that can either lose or accept a proton and thus can function as either a Bronsted–Lowry acid or a Bronsted–Lowry base. ❑ The absolute structural requirement for an amphiprotic substance is the presence of both a hydrogen atom and a lone pair of electrons. Water is the most common amphiprotic substance. Conceptual Definition of Acids and Bases Lewis Acids and Bases ❑ Lewis acid is a species that accepts an electron pair (i.e., an electrophile) and will have vacant orbitals. ❑ Lewis base is a species that donates an electron pair (i.e., a nucleophile) and will have lone-pair electrons. ❑ Consider the structure of ammonia with its free pair of electrons. If the free pair of electrons were to make a bond with boron trifluoride, which substance is labeled as an acid and which one is the base? Because the boron accepted a pair of electrons it is considered to be the Lewis acid. Ammonia is the substance that donated the electron pair and is classified as the Lewis base Conceptual Definition of Acids and Bases Physical Properties and Their Uses Acid ❑ Taste sour ❑ Forms H+ ions in solution ❑ 2HCl + 2Na → 2NaCl + H2 ❑ pH less than 7 ❑ Neutralizes bases ❑ Corrosive-reacts with most metals to form hydrogen gas ❑ Good conductors of electricity ❑ Common examples and its uses HCl - hydrochloric acid - stomach acid HC2H3O2 - acetic acid – vinegar H2SO4 - sulfuric acid - car batteries H2CO3 - carbonic acid – sodas HNO3 - nitric acid - explosives H3PO4 - phosphoric acid -flavorings Conceptual Definition of Acids and Bases Physical Properties and Their Uses Base ❑ Taste bitter ❑ Feel slippery ❑ Conduct electricity ❑ Sometimes Caustic. That is, they eat away at certain substances and they are irritating or damaging to skin. ❑ pH greater than 7 ❑ Usually forms OH- ions in solution ❑ Neutralizes acids NaOH - sodium hydroxide (LYE) soaps, drain cleaner Al (OH)3 - aluminum hydroxide - antacids, deodorants Mg (OH)2 - magnesium hydroxide - antacids NH4OH - ammonium hydroxide - “ammonia” Salt Concept ❑ A salt is a compound formed from the positive metal ions of a ❑ base and a negative nonmetal ion of an acid. ❑ For example: NaCl and K2SO4 ❑ Are the product of a reaction between an acid and a base, along with water. Properties ❑ They form crystals when in solid form ❑ They usually have a higher hardness because of their ionic bonding. ❑ An acid plus a base yield a salt and water. Salt: Salts That Yield Neutral Solutions ❑ A salt consisting of the anion of a strong acid and the cation of a strong base yields ❑ a neutral solution because the ions do not react with water. ❑ When a strong acid such as HNO3 dissolves, the reaction goes essentially to completion because the anion of a strong acid is a much weaker base than water. The anion is hydrated, but it does not react with water: ❑ Similarly, a strong base, such as NaOH, dissolves completely. The cation, in this case Na+, is hydrated, but it is not small and charged enough to react with water: Salts That Yield Acidic Solutions ❑ A salt consisting of the cation of a weak base and the anion of a strong acid yields an acidic solution because the cation acts as a weak acid, and the anion does not react. ❑ For example, NH4Cl yields an acidic solution because NH4+, the cation of the weak base NH3, is a weak acid; Cl2, the anion of the strong HCl, does not react: Salts That Yield Basic Solutions ❑ A salt consisting of the anion of a weak acid and the cation of a strong base yields a basic solution because the anion acts as a weak base, and the cation does not react. ❑ Sodium acetate, for example, yields a basic solution because the CH3COO- ion, the anion of the weak acid CH3COOH, acts as a weak base; Na+, the cation of the strong base NaOH, does not react: Summary of Acid Base Properties of Salts https://chem.libretexts.org/Bookshelves/General_Chemistry/Map%3A_Chemistry_(Zumdahl_and_Decoste)/7%3A_Acids_and_Bases/7.08_Acid-Base_Properties_of_Salts Summary of Acid Base Properties of Salts https://chem.libretexts.org/Bookshelves/General_Chemistry/Map%3A_Chemistry_(Zumdahl_and_Decoste)/7%3A_Acids_and_Bases/7.08_Acid-Base_Properties_of_Salts Oxides Concept ❑ Oxides are chemical compounds with one or more oxygen atoms combined with another element (e.g. Li2O). ❑ Oxides are binary compounds of oxygen with another element, e.g., CO2, SO2, CaO, CO, ZnO, BaO2, H2O, etc. ❑ These are termed as oxides because here, oxygen is in combination with only one element, in which it usually has a valency of 2 minus, often with a release of large amounts of energy. Oxides Oxides are very common in nature owing to the fact that the air consists of about 20% oxygen. Many metals occur as ores containing oxides. This makes them very important economically. Examples: ❑ Al2O3 - Bauxite is important for the industrial production of aluminium by electrolysis (The Hall Process) ❑ Fe2O3 - Haematite is important for the industrial extraction of iron (The blast furnace, Bessemer Process) Ionic and covalent oxides ❑ Ionic bonding occurs when there is a large difference in electronegativity between two elements. Oxygen is highly electronegative and forms ionic bonds with all metals Sodium oxide is a typical ionic oxide. It consists of a giant structure of sodium ions and oxide ions. It displays the ionic character typical of a giant ionic structure, high melting point and electrical conductor when molten. Oxides Ionic and covalent oxides ❑ Covalent oxides are formed when oxygen reacts with non-metals Sulfur (IV) oxide (sulfur dioxide) is a typical simple covalent oxide. It consists of individual molecules of the formula SO2. It has typical simple covalent properties such as low melting point and electrical insulator (non-conductor) when in the liquid. state. Types of Oxides: Acid and Bases Most oxides can be grouped into four types: ❑ acidic oxides ❑ basic oxides ❑ amphoteric oxides ❑ neutral oxides Acidic oxides ❑Non-metals react with oxygen to form acidic compounds of oxides which are held together by covalent bonds. ❑Also be called as acid anhydrides. ❑have a low melting and boiling point ❑except for compounds like B2O3 and SiO2 which have high melting points and form giant React with water to produce acids. molecules. Example: ❑Examples: NO, CO2 Sulphur trioxide + water → Sulfuric acid ❑React with water to produce acids. Example: Sulphur trioxide + water → Sulfuric acid SO3 + H2O → H2SO4 Boric oxide + water → Boric acid B2O3 + H2O → 2H3BO3 Basic oxides ❑Metals react with oxygen to give basic compounds of oxygen. ❑These compounds are usually ionic in nature. Group 1, 2 and lanthanides form basic compounds of oxygen when they react with dioxygen. ❑During the formation of these compounds, a large amount of energy is released. ❑These compounds readily react with water except a few exceptions. ❑Examples: M2O3, MO2, ThO2 ❑React with water to produce base. Example: Sodium oxide + water → Sodium hydroxide Na2O + H2O → 2NaOH Amphoteric oxides ❑Compounds of oxygen which exhibits both acidic as well as basic characteristics. ❑These oxides when reacting with acid undergoes a neutralization reaction to form water and salt. ❑This exhibits the basic property of the compounds. ❑Similarly reacts with the alkali to form salt and water, exhibiting acidic property. ❑Example: aluminium oxide (Al2O3) ❑React with acids and alkalis to produce salts Example: ❑Basic characteristics Al2O3 + 6HCl → 2Al3+ + 6Cl– + 3H2O ❑Acid characteristics Al2O3 +2OH– + 3H2O → 2[Al (OH)4]– Neutral oxides ❑Some compounds react with oxygen to form oxides which do not exhibit acidic nor basic characteristics. ❑Such compounds are called as neutral compounds of oxygen. ❑Tend React to be with of low water solubilitytoinproduce water and have no effect in litmus paper. acids. Example: ❑Example: carbon monoxide (CO), nitrous oxide (N2O), nitric oxide (NO) Sulphur trioxide + water → Sulfuric acid All ionic compound names give the positive ion (cation) first and the negative ion (anion) second. Compounds Formed from Monatomic Ions Sample Problem: Name and Write the Binary Ionic Compounds a. Name the ionic compound: Magnesium and nitrogen b. Write the empirical formula: Cs+ and S2- Silberberg, M. (2010) Principles of General Chemistry 2nd Edition, New York: McGraw-Hill Many metals, particularly the transition elements (B groups), can form more than one ion, each with its own particular charge. Compounds with Metals That Can Form More Than One Ion For example, iron can form Fe2+ and Fe3+ ions. The two compounds that iron forms with chlorine are FeCl2, named iron (II) chloride (spoken “iron two chloride”), and FeCl3, named iron (III) chloride. Sample Problem: Give the… a. Formula: tin(II) fluoride b. Name: CrI3 Silberberg, M. (2010) Principles of General Chemistry 2nd Edition, New York: McGraw-Hill Remember that the polyatomic ion stays together as a charged unit. When two or more of the same polyatomic ion are present in the formula unit, that ion appears in parentheses with the subscript written outside. Compounds Formed from Polyatomic Ions For example, calcium nitrate, which contains one Ca2+ and two NO3- ions, has the formula Ca (NO3)2. Parentheses and a subscript are not used unless more than one of the polyatomic ions is present; thus, sodium nitrate is NaNO3, not Na (NO3). Families of Oxoanions With two oxoanions in the family: The ion with more O atoms takes the nonmetal root and the suffix -ate. The ion with fewer O atoms takes the nonmetal root and the suffix -ite. Silberberg, M. (2010) Principles of General Chemistry 2nd Edition, New York: McGraw-Hill When naming them and writing their formulas, we consider them as anions connected to the number of hydrogen ions (H+) needed for charge neutrality. Acid Names from Anion Names 1. Binary acid solutions form when certain gaseous compounds dissolve in water. For example, when gaseous hydrogen chloride (HCl) dissolves in water, it forms a solution whose name consists of the following parts: 2. Oxoacid names are similar to those of the oxoanions, except for two suffix changes: Silberberg, M. (2010) Principles of General Chemistry 2nd Edition, New York: McGraw-Hill  When two nonmetals combine with each other, the product is most often a binary molecular compound. To name a covalent compound or molecular compound, name first the first nonmetal. The second non-metal is named by changing its suffix with –ide. * One exception of using these prefixes is that the first element in the formula never uses the word “mono”. N2O4 = dinitrogen tetroxide Masterton, W.L. and Hurley, C.N. (2016) Chemistry Principle and Reactions, 8th edition. Canada: Brooks/Cole-Cengage Learning MIND CHECK!!! Which of the following combinations would need roman numerals in the name? Name the following ionic compound: BeCl2 a. Potassium and Fluorine b. Boron and Iodine beryllium chloride c. d. Beryllium and Oxygen Gold and Oxygen The chemical formula of sulfur The name of P₄S₁₀ is ___. a. phosphorous sulfide hexabromide is __________. b. phosphorus sulfide SBr₆ c. phosphorus (X) sulfide d. tetraphosphorus decasulfide References: 1. Brown, T.L., LeMay Jr., H.E., Bursten, B.E., Murphy, C.J., Woodward, P.M. (2011) Chemistry – The Central Science, 12th ed., Prentice-Hall International Inc. 2. Chang, R. and Goldsby, K. (2016) Chemistry, 12th International Edition, New York: McGraw- Hill 3. Masterton, W.L. and Hurley, C.N. (2016) Chemistry Principle and Reactions, 8th edition. Canada: Brooks/Cole-Cengage Learning 4. Silberberg, M. (2010) Principles of General Chemistry 2nd Edition, New York: McGraw-Hill