Chemistry Past Paper - Ionic Compounds PDF

Topic 4 Chemical Bonding Concept B: Writing and Naming Formulas of Ionic Compounds  Chemical Names and Formulas – Ch. 7 S. 1 Lesson Objectives Jens Martensson  To analyze the significance of a chemical for...

Topic 4 Chemical Bonding Concept B: Writing and Naming Formulas of Ionic Compounds  Chemical Names and Formulas – Ch. 7 S. 1 Lesson Objectives Jens Martensson  To analyze the significance of a chemical formula i.e. symbols and subscripts.  To determine the formula of an ionic compound from its name. Key Vocabulary monoatomic ions binary compounds polyatomic ions nomenclature 2  What is the name of the ionic compound CuCl2? A. copper chloride Jens Martensson B. copper chlorine C. copper dichloride D. copper (II) chloride #15 3  Significance of a Chemical Formula A chemical formula is used to represent a chemical compound. Symbols are used to represent type of atom. Subscripts are used to represent number of each type of atom Jens Martensson present. 4  Slide 5 Try Its! 1) How many atoms are 2) How many atoms of H there total in: H2SO4? are there in (NH4)2CrO4 A. 3 A. 2 Jens Martensson B. 5 B. 4 C. 6 C. 6 D. 7 3) Which elements areD. 8 present in NaCO3? A. sodium and cobalt B. sodium, copper, and oxygen C. sodium, carbon, and oxygen D. nitrogen, aluminum and 5 copper  Monatomic Ions Monatomic ions: ions formed from a single atom. Jens Martensson Most common ions 6  Writing Formulas for Ionic Compounds Crisscross method 1. Write the symbols for the ions side by 1 side. Write the cation first. Jens Martensson 2. Drop +/- sign. Criss cross the numbers as the subscript for the 2 other ion. 3. Check the subscripts and divide them by their largest common factor to give the smallest possible whole-number ratio of ions. Then write the formula. 3 7  Slide 8 Try Its! Determine the chemical formula for the Jens Martensson ionic compound the following ions would make: 1) Na1+ and Cl1- 2) Ca2+ and F1- 3) Mg2+ and S2- 4) Al3+ and O2- 8  Naming Monatomic Ions Monatomic cations are identified simply by the element’s name. Jens Martensson Monatomic anions: element’s root name + ide Some elements (mostly transition metals) can form cations with various Stock System charges. Roman numeral in parenthesis is used to 9 identify charge (this naming  Naming Binary Ionic Compounds Nomenclature: naming system for chemical compounds. Binary compounds: compounds composed of two elements. Steps: Jens Martensson 1. Name of cation 2. Name of anion Sample Problem 1 Write the formula and name the ionic compound that would form from the following elements: a. potassium and chlorine b. magnesium and chlorine c. calcium and sulfur d. copper (II) and oxygen 10  Naming Binary Ionic Compounds Metal Charges Metal Charges Metal Charges *Use Roman numeral after Titanium Ti2+, Ti3+, Ti4+ Cobalt Co2+, Co3+ Lead Pb2+, Pb4+ name of metal to show charge. Vanadiu V2+, V3+, V4+, Nickel Ni2+, Ni3+ Iron Fe2+, Fe3+ Example: Jens Martensson m V5+ Co2+ is called Chromiu Cr2+, Cr3+, Copper Cu1+, Cu2+ Tin Sn2+, Sn4+ cobalt (II) m Metal Cr6+ Charge Mangane Zinc MnZn 2+ ,2+Mn4+, Mercury Sample Problem 2 Hg1+, Hg2+ se Mn7+ Name the following ionic compounds: Cadmium Cd2+ Silver Ag+ a. SrF2 b. BaO *No need to use Roman numeral for metals that only c. ZnO have 1 possible charge. d. Fe2O3 Example: Ag+ is called silver e. FeO 11 f. SnO2 Slide 12 Try Its! Name the following ionic compounds: 1) BaF2 2) CaO Jens Martensson 3) AgF 4) CdO 5) K3N 6) AlBr3 7) CoF3 8) SnI4 9) FeS 10) PbS2 12  Naming Ionic Compounds containing Polyatomic Ions Most polyatomic ions are negatively charged, and most are oxyanions – polyatomic ions that contain oxygen. Jens Martensson 13  Naming Ionic Compounds containing Polyatomic Ions Sample Problem 3 Write the chemical formula for each ionic compound formed. Jens Martensson sulfide sulfite sulfate tin(IV) aluminu m lithium Sample Problem 4 Write the name for each of the following ionic compounds: a. Ca(OH)2 b. KClO3 c. NH4OH 14 d. Fe2(CrO4)3  Slide 15 Try Its! 1) Write chemical 2) Give the names of the formulas for the following ionic Jens Martensson following ionic compounds: compounds: A. Ag2S A. copper(II) nitrate B. NaMnO4 B. potassium iodide C. NH4NO3 C. sodium hydroxide D. ammonium acetate D. FePO4 15