Ionic Compounds: Formulas & Names PDF

3.2 Names and Formulas for Ionic Compounds 3.2.1Explain the energy transformation when an ionic bond forms while identifying the type of elements involved and the movement of electrons. 3.2.2 Use the Lewis diagram (electron-dot structure) to explain how elements from the periodic groups combine to f...

3.2 Names and Formulas for Ionic Compounds 3.2.1Explain the energy transformation when an ionic bond forms while identifying the type of elements involved and the movement of electrons. 3.2.2 Use the Lewis diagram (electron-dot structure) to explain how elements from the periodic groups combine to form an ionic compound. 3.2.3 Investigate the physical properties of ionic compounds, such as melting and boiling points, conductivity when solid, molten, or aqueous, and solubility in water. 3.2.4 Lab 3 – Experiment to study the properties of ionic compounds (Solubility, conductivity, physical properties) 3.2.5 Describe how formula units relate to the composition of an ionic compound. 3.2.6 Write the chemical name of an ionic compound containing monoatomic and polyatomic ions (including oxyanions). 3.2.7 Write the chemical formula (using the stock method) of an ionic compound containing monoatomic and polyatomic ions. Resource: Inspire Chemistry – Module 6 – Lesson 3 1 Recall When metals and non metals bond, there is a transfer of valence electrons from the metal species to the non metal species. This is called Ionic bonding Use the Lewis diagram to explain the type of chemical bonding in Magnesium and Sulphur. 3.2.1-3.2.2 2  Physical Properties of Ionic Compounds Crystal Lattice The crystal lattice is a three- dimensional geometric arrangement of particles. In a crystal lattice, each positive ion is surrounded by negative ions, and each negative ion is surrounded by positive ions. 3.2.3 3  Physical Properties of Ionic Compounds Crystal Lattice 1. Ionic crystals are hard, rigid, and brittle solids due to the strong attraction between electric charges that holds the ions in place. 3.2.3 4  Physical Properties of Ionic Compounds Crystal Lattice 2. High melting point and boiling point – Large amount of energy is needed to overcome the strong electrostatic force of attraction between oppositely charged particles 3.2.3 5  Physical Properties of Ionic Compounds Crystal Lattice 3. Ionic Compounds are often Soluble in water. 3.2.3 6  Physical Properties of Ionic Compounds Think-Pare-Share Observe the given image and give reason(s) for why the bulb didn’t glow in A and B but lights up in C. Hint: Relate it chemical bonding and any think of any other possible reason(s). 4. Poor conductivity when solid because ions are not free to move and carry electric current. High conductivity when molten or aqueous because ions are free to move and carry electric current 3.2.3 7 Group Task Physical Properties of Ionic Compounds 1. Use the simulation to complete the table below: 3.2.3 8  Summary Physical Properties of Ionic Compounds Property Explanation High melting and boiling High melting point and boiling point – Large amount of energy is needed to overcome points the strong electrostatic force of attraction between oppositely charged particles Hard and brittle Ionic compounds are brittle due to the strong bond between the positive and negative ions that make up the molecules. These positive and negative bonds create crystals in rigid, lattice structures. Applying pressure shifts the alignment of the ions and results in brittleness. Conduct electricity ONLY as Poor conductivity when solid because ions are not free to move and carry electric liquids, NOT as solids current. High conductivity when molten or aqueous because ions are free to move and carry electric current Soluble in water, not in non The most ionic compounds are soluble in polar solvent. The reason is that the polar polar substances solvents decrease the electrostatic force of attraction which is present between the ions in the compound and get dissociated easily. Solids are good insulators Poor conductivity when solid because ions are not free to move and carry electric current. 3.2.3 Formula Units Formula unit is the simplest ratio of the ions represented in an ionic compound. The formula unit of magnesium chloride is MgCl2 because the magnesium and chloride ions exist in a 1:2 ratio. What is the simplest ratio of the ions represented in NaCl? 3.2.5 10 Formula Units Ionic Solids / Ionic Compounds Crystal Lattice is Charge Neutral NaCl; 1 Na cation and 1 Cl anion. Ratio 1:1 3.2.5 11 Polyatomic Ions is an ion made up of more than one atom. 12 Oxyanion Ions is polyatomic ion composed of an element, usually a nonmetal, bonded to one or more oxygen atoms. 13 Chemical Formula Ionic Compounds 3.2.7 14 Chemical Formula Ionic Compounds 3.2.7 15 Chemical Formula Ionic Compounds 3.2.7 16 Chemical Formula Ionic Compounds 3.2.7 17 Naming Ionic Compounds Given chemical formula. Without polyatomic ion 3.2.6 18 Naming Ionic Compounds Without polyatomic ion Write the name of the compound formed from Potassium and oxygen. Potassium Oxide 3.2.6 19 Naming Ionic Compounds Given chemical formula. With polyatomic ion 3.2.6 20 Naming Ionic Compounds With polyatomic ion 1. Write the name of the compound formed from Potassium and Nitrate (KNO3). PotassiumNitrate 2. Write the name of the compound NH4OH? Ammoniu Hydroxide m 3. Write the name of the compound (NH4)2S? Ammoniu Sulfide m 3.2.6 21