Chemical Equations Part 1 A Directed Learning Activity for Hartnell College Chemistry 1 Funded by the Title V – STEM Grant #P031S through Hartnell College For information contact Start

Student Learning Objectives This tutorial will help you to: 1. Predict products of single and double- replacement reactions 2. Generate formula, total ionic and net ionic equations using solubility and acid strength information Next

Getting Started This set of Power Point slides will lead you through a series of short lessons and quizzes on the topics covered by this Directed Learning Activity tutorial. Move through the slideshow at your own pace. There are several hyperlinks you can click on to take you to additional information, take quizzes, get answers to quizzes, and to skip to other lessons. You can end this slide show at any time by hitting the ESC key on your computer keyboard. Next

Table of Topics What You Should Know Classes of Chemical Reactions Single-replacement Reactions Double-replacement Reactions Next Slide

What You Should Know Write correct chemical formulas for elements, ions and compounds Balance chemical formula equations Know the difference between strong and weak acids and bases in solution Next Slide

Classes of Chemical Reactions A Quick Overview of Synthesis, Decomposition, Single and Double-replacement Reactions Next Slide

The Four Major Classes of Chemical Reactions There are many different types of chemical reactions, but they can be broken down into these major categories: Synthesis (Combination) Reactions Decomposition Reactions Single-Replacement Reactions Double-Replacement Reactions The next few slides will explain the general characteristics of each category Next Slide

Synthesis (Combination)Reactions Next Slide

Decomposition Reactions Next Slide

Single-replacement Reactions Next Slide

Double-replacement Reactions Next Slide

Details of Single- replacement Reactions Next Slide

Example: A Metal Replaces Another Metal in a Compound Next Slide

Example: A Metal Replaces H to Form H 2 (g) Next Slide

Example: A Nonmetal Replaces Another Nonmetal Next Slide

Quiz Questions Answers to Quiz Questions

Next lessonReview this lesson

Double-replacement Reactions Next slide

Example: Reactions in Solution that Form a Precipitate Next Slide

Example: Reactions that Form a Gas Next Slide

Example: Reactions that Form Water Next Slide

Quiz Questions Check answers

Answers to Quiz Questions Next lessonReview lesson

Net Ionic Equations Getting Rid of the Spectators Next slide

Representing Reactions When a reaction occurs in aqueous solution, we can write the formula equation, which uses the neutral formulas or symbols for the reactants and products. These are the kinds of equations you have already practiced writing. In certain instances, there are other ways of representing the reaction. The total ionic equation (TIE) separates all the neutral compounds into the ionic species they form in solution. The net ionic equation removes those ions from the equation that do not result in creating a new product. Those ions are called spectator ions, since they dont actually participate in the formation of a new product. Next slide

Example: Precipitation Next slide

If we now break down everything that is soluble into ions and rewrite the equation, we obtain the total ionic equation : Ca 2+ (aq) + 2 NO 3- (aq) + 2 Na + (aq) + CO 3 2- (aq) CaCO 3 (s) + 2 Na + (aq) + 2 NO 3- (aq) Inspecting this equation, we see that there are several ions that appear on both sides of the equation. These are the spectator ions. If we remove these, we obtain the net ionic equation : Ca 2+ (aq) + 2 NO 3- (aq) + 2 Na + (aq) + CO 3 2- (aq) CaCO 3 (s) + 2 Na + (aq) + 2 NO 3- (aq) or Ca 2+ (aq) + CO 3 2- (aq) CaCO 3 (s) Next slide

We can do similar procedures to the formula equations for the reactions that form gases and for neutralization of acids and bases. What if you are only given the starting materials and have to predict the products of the formula equation before you generate the net ionic equation? Then, you will have a use a table of solubilities like to the one on the next slide. There is probably one similar to it in your lecture text. You also need to know if the acids and bases are weak or strong. Remember that weak acids and bases do not completely dissociate and will be molecular species in solution. There is also an example table of strong acid and base on another slide. Solubility Table

Anions CationsC2H3O2-C2H3O2- AsO 4 - Br - CO 3 2- Cl - CrO 4 2- OH - I - NO 3 - C 2 O 4 2- O 2- PO 4 3- SO 4 2- S 2- SO 3 2- Al 3+ aqI - -I -II d- NH 4 + aq - Ba 2+ aqI I Isl. aqaq Isl. aqIIdI Bi 3+ -sl. aqdId-IIaqIIsl. aqdI- Ca 2+ aqI I I IIIIdI Co 2+ aqI I II III II Cu 2+ aqI I II- III I- Fe 2+ aqI sl. aqaq-I III Isl. aq Fe 3+ IIaqI II- II I- Pb 2+ aqIIIIIII IIIIII Mg 2+ aqd I I III dsl. aq Hg 2 2+ sl. aqIIII -IaqIIIII- Hg 2+ aqIII sl. aqIIaqIIIdI- Ni 2+ aqI I II III II K + aq Ag + sl. aqIIIII-IaqIIIIII Na + aq Sr 2+ aq- I I --III- Zn 2+ aqI I II III II NextNext

Examples of Strong Acids & Bases Strong acids in aqueous solutions: HClO4, H 2 SO4, HI, HBr, HCl, HNO 3 Strong bases in aqueous solutions: LiOH, KOH, NaOH, Ca(OH) 2 Remember that strong refers to species that dissociate (almost) completely to ions in water. Next slide

Quiz Questions Write the net ionic equations for these reactions: K 2 SO 4 (aq) + BaBr 2 (aq) ? + ? Na 2 CO 3 (aq) + 2 HCl (aq) ? + ? + ? Ca(OH) 2 (aq) + 2 HCl (aq) ? + H 2 O (l) Next slide

Answers to Questions K 2 SO 4 (aq) + BaBr 2 (aq) 2 KBr (aq) + BaSO 4 (s) Ba 2+ (aq) + SO 4 2- (aq) BaSO 4 (s) Comment: look at solubility of the possible products to see that one of the products is solid. Delete the spectator ions to yield the net ionic equation. Na 2 CO 3 (aq) + 2 HCl (aq) 2 NaCl (aq) + H 2 O (l) + CO 2 (g ) 2 H + (aq) + CO 3 2- (aq) H 2 O (l) + CO 2 (g ) Comment: Refer to gas generation example. Delete the spectator ions to generate the net ionic equation. Next slide

Ca(OH) 2 (aq) + 2 HCl (aq) CaCl 2 (aq) + 2 H 2 O (l) 2 H + (aq) + 2 OH - (aq) 2 H 2 O (l) Comment: This net ionic equation is common to all acid-base neutralization reactions Review lesson Next slide

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