Naming Simple Ionic Compounds PDF

Summary

The document discusses the naming of simple ionic compounds, covering both the classical and stock systems for naming compounds with varying charges. It provides examples and rules for naming these compounds.

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SCIENCE 9 Naming of Simple Ionic Compounds For a basic ionic compound, (one that uses a metal cation and a non-metal anion) the metal cation simply uses the name of the element, and the non-metal anion uses the name of the element with the suffix changed...

SCIENCE 9 Naming of Simple Ionic Compounds For a basic ionic compound, (one that uses a metal cation and a non-metal anion) the metal cation simply uses the name of the element, and the non-metal anion uses the name of the element with the suffix changed to - ide. ex: AlF3 ex: NaCl ex: LiF Aluminum + Fluorine Sodium + Chlorine Lithium + Fluorine = Aluminum Fluoride = Sodium Chloride = Lithium Fluoride Other Ways of Naming Ionic Compounds For the case of an element that have varying charges, two ways of naming/nomenclature can be used. It can be the classical system of naming compounds or the stock system of naming compounds. Classical System Name The common system or the classical system, uses the suffixes "-ic" and "-ous" to indicate the charge of the cation. The "-ic" suffix represents the greater charge, and the "-ous" suffix represents the lower charge. ex: Lead (Pb) is an element that can have varying charges depending on the element they are bond with. Its charge can vary from +2 or +4 charge. Hence, by using the classical system, we named this element as either: Plumbous: refers to lead ions with a +2 charge, represented as Pb2+ Plumbic: refers to lead ions with a +4 charge, represented as Pb4+ In the case of this ionic compound: Pb2O4 = PbO2, we called it as Plumbic oxide as the charge of lead in this ionic compound was +4. Stock System Name The Stock system is a chemical nomenclature system that uses Roman numerals to indicate the oxidation state/charge of an element in a compound or ion. In our given example awhile ago, Lead (Pb) is an element with varying charges (2+ or 4+). Instead of using the classical system, we can also name this element by using Roman Numerals to represent its charges. By using the stock system, we named this element as either: Lead (II): refers to lead ions with a +2 charge, represented as Pb2+ Lead (IV): refers to lead ions with a +4 charge, represented as Pb4+ In the case of this ionic compound: Pb2O4 = PbO2, we can also name it as Lead (IV) oxide as the charge of lead in this ionic compound was +4. Other common elements (metals) that used these two types of nomenclature are the following: Element & Symbol Charges Classical System Stock System 2+ Plumbous Lead (II) Lead (Pb) 4+ Plumbic Lead (IV) 2+ Ferrous Iron (II) Iron (Fe) 3+ Ferric Iron (III) 1+ Cuprous Copper (I) Copper (Cu) 2+ Cupric Copper (II) 2+ Stannous Tin (II) Tin (Sn) 4+ Stannic Tin (IV) Naming of Simple Covalent Compounds Rules for naming simple covalent compounds: 1. Name the non-metal furthest to the left on the periodic table by its elemental name. 2. Name the other non-metal by its elemental name and an -ide ending. 3. Use the prefixes mono-, di-, tri-.... to indicate the number of that element in the molecule. 4. If mono is the first prefix, it is understood and not written. Examples: PROPERTIES OF IONIC AND COVALENT COMPOUNDS Another difference between Ionic and Covalent compounds aside from its nature (either transferring or sharing of valence electrons) is its varying properties. Ionic and covalent compounds have different physical and chemical properties. Example of common properties includes the following: Crystals: Most crystals are ionic compounds. This is because the ions in these compounds tend to stack into crystal lattices to balance between the attractive forces between opposite ions and the repulsive forces between like ions. Covalent or molecular compounds can exist as crystals, though. Examples include sugar crystals and diamond. Example of ionic compound that forms crystals is Sodium Chloride (NaCl). Crystals formed by a stack of Sodium Chloride (NaCl) compound (+) (-) Electrostatic attraction between unlike charges In this given compound, the differences between the resulting charges of Sodium (Na1+) and Chlorine (Cl1-) during ionic bonding results to an electrostatic attraction between the two elements. More number of Sodium Chloride (NaCl) compounds stack together formed crystals. We called these resulting crystals as salt/table salt. Melting and boiling points: Ionic compounds tend to have higher melting and boiling points than covalent compounds. This happens because ionic compounds often form crystal lattice structures, a highly organized and stable structure, that require a large amount of energy to break. Covalent compounds on the other hand, formed molecular structures, where individual molecules are held together by weaker intermolecular forces. These weaker forces require less energy to overcome. Mechanical properties: Ionic compounds tend to be hard and brittle while covalent compounds tend to be softer and more flexible. Electrical conductivity and electrolytes: Ionic compounds conduct electricity when melted or dissolved in water while covalent compounds typically don't. This is because covalent compounds dissolve into molecules while ionic compounds dissolve into ions (cation or anion), which can conduct charge. For example, salt (sodium chloride) conducts electricity as molten salt or in salt water. If you melt sugar (a covalent compound) or dissolve it on water, it won't conduct electricity.

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