120 likes | 281 Views
Review (Partner Talk). When each of these are released in water, what ions are released and in what ratios? Li 3 N, b) Fe 2 O. 2) When a metal and non-metal react: a) which one will pull electron(s) from the other.
E N D
Review (Partner Talk) When each of these are released in water, what ions are released and in what ratios? Li3N, b) Fe2O. 2) When a metal and non-metal react: a) which one will pull electron(s) from the other. b) which will form the cation and which will form the anion. 3) Why are ionic compounds called electrolyte?
Names and Formulas of Ionic Compounds • Names of ionic compounds have two parts. • First part is the metal • Second part is the non-metal. • Name of metal ion remain the same. • The ending of the non-metal changes to “ide”. eg.
Writing Chemical Formulas of Ionic Compounds Method One. Beryllium fluoride Step One: Be F (symbols, metal is written first) Step Two: +2 -1 (add charge above symbols) Be F Step Three: 1(+2) + 2(-1) = 0 (make total ionic charge zero) Step Four : Be1F2 (write formula using red coefficients as subscripts) Step Five BeF2 (do not write subscript 1, the symbol rep. one ion)
Writing Chemical Formulas of Ionic Compounds • Method One. • Sodium sulfide Step One: (symbols, metal is written first) Step Two: (add charge above symbols) Step Three: (make total ionic charge zero) Step Four : (write formula using coefficients as subscripts) Step Five (do not write subscript 1, the symbol rep. one ion)
Writing Chemical Formulas of Ionic Compounds • Method Two (Crisscross Method) • Beryllium fluoride Step one: Be +2 F -(symbol and ionic charge) Step two: Be +2 F - BeF2 (crisscross no. of charges for them to become subscripts) Formula is BeF2
Writing Chemical Formulas of Ionic Compounds • Method two: Sodium sulfide Step one: (symbol and ionic charge) Step two: (crisscross no. of charges for them to become subscripts) Step three: (write formula)
Metals with multiple of ionic charge (Use Roman numerals to complete
Naming Compound With Multiple Ionic Charge • Note. You must determine the ionic charge of the metal and include it in the name. • Eg. FeCl3. is called iron (111)chloride.
Summary • When writing chemical formula of ionic compounds, the number of each ion must balance the positive and negative charges. • The number of ions must be the simplest ratio in the formula. The subscript 1 is not included. • The metal ion is written first. The ending of the non-metal ion is changed to “ide”. • Some metals can form ions with different charges. The charge for these are written in Roman numerals in brackets after the metal name.
Homework/Class Work • Page 200 of text. • 1) Discuss the answers to questions 1 to 8 with your partner. • 2) Complete question 9 in your binder (individual work).