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Science Says… …How Olympians Have Changed. http:// www.cbc.ca/sochi2014/sciencesays/video/the-science-of-stretching-and-warming-up. Learning goals:. By the end of class, I will be able to: Write the formula AND name the chemical formula for ionic compounds
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Science Says……How Olympians Have Changed • http://www.cbc.ca/sochi2014/sciencesays/video/the-science-of-stretching-and-warming-up
Learning goals: • By the end of class, I will be able to: • Write the formula AND name the chemical formula for ionic compounds • Recognize multivalent elements on the periodic table • Write the formula AND name multivalent compounds
RECAP: What do we know about ionic compounds??? • Ionic compounds exist between a metal and non-mental • The overall charge of an ionic compound is 0. • To name ionic compound, write the metal first and the non-metal second, change the ending of the non-metal to “ide”
Review Naming & Writing Univalent Ionic Compounds • MgS • NaCl • Al2O3 • Calcium sulphide • Zinc phosphide • Calcium iodide • Potassium fluoride
Challenge #1 – Complete with a Partner • Are the following ionic compounds possible? Explain why or why not. • (a) Ca2P3 • (b) LiI • (c) NaBr
Crisscross Rule for Writing Formulas Step 1: Write the symbols of each element (remember to write the symbol for the metal first) Step 2: Write the ion charge above each corresponding symbol. Remember that the ion charge is based on the number of electrons gained (negative) OR lost (positive) to become an ion. Step 3: Crisscross the ion charges, erase the signs of each ion charge, and write them as subscripts
Examples of Writing Formulas • Write the correct formula for a compound of aluminum and sulphur • (a) 3+ 2- Al S = Al2S3
Examples of Writing Formulas • Write the correct formula for a compound of barium and oxygen • (b) 2+ 2- Ba O = Ba2O2 Note: If you need the same number of each ion, you can reduce the formula to one of each ion, as shown here. = BaO
Challenge #2 – Complete with a Partner • What do you do if an ion has two or more possible charges? • Give examples to support your answer.
Multivalent Elements • A metal that can form an ion in more than one way • Which elements in the periodic table have more than one ionic charge? • the name of an ion of a multivalent metal ALWAYS contains a Roman numeral that indicates the ion charge • ONLY multivalent metals have Roman numerals!!! Eg: Copper 1+ is named copper (I) Copper 2+ is named copper (II)
Multivalent Compounds • The roman numeral indicates the ionic charge of the multivalent metal Eg: Copper (II) chloride 2+ 1- Copper (II) chlorine CuCl2
Example: • Name this multivalent compound: • MnO2 • Write the formula for this multivalent compound • Copper (II) oxide
Practice Naming & Writing Multivalent Ionic Compounds Platinum(IV) oxide Iron(III) sulfide Copper(I) oxide • TiF4 • Cr3P2 Sn3N4
Stump your partner • On a sheet of paper, write down the chemical formula or name of 10 compounds • 5 should be ionic compounds • 5 should be multivalent ionic compounds • Switch papers with a partner and see if you can name or write the formula for their compounds!
Magnesium Oxide • Aluminum Oxide Potassium Chloride Sodium Bromide • Lithium Oxide • Nickel (II) Phosphide • Zinc Oxide • Mercury (I) Oxide Cobalt (II) Oxide Iridium Nitride • Li2O • CaBr2 • Ni3N2 KI • SnBr4 • Al2S3 • Cd3N2 • Fe203 • CuCl • AuF