Chapter 8: Reaction in Aqueous Solutions Chapter Goals If given reactants be able to 1.Predict what products could be formed. 2.Predict what state those products will be in. 3.Identify the type of reaction that has happened.

I. Understanding Aqueous Solutions A.How to predict if a reaction will happen. 1.If a solid will be produced 2.If a gas will be produced 3.If water will be produced 4.If electrons will be transferred Review: What are the 4 things that indicate if a reaction will happen?

B.What happens when an ionic compound dissolves in water?What happens when an ionic compound dissolves in water? 1. The ions separate and move around independently. a)NaCl (s)  b)Ba(NO 3 ) 2  c)Potassium Sulfide: 2.Strong Electrolyte: A substance that dissolved completely in water. Draw a molecular level diagram of what you think an NaCl solution Looks like.

C.Predicting what products will form from a reaction done in water. 1. Determine all of the ions that are present in the solution. 2. List the possible ways the ions could recombine to form new products. a)Remember that compounds must end up with a neutral charge. 3.Use your logic to make the best possible choice of products. Ba(NO 3 ) 2 (aq) + K 2 S (aq)  AgNO 3 + NaCl 

D.Precipitation Reactions: Reactions that produce a solid. 1.Precipitate: A solid that is formed in a reaction. 2.Predicting Precipitates (Solids) a.Soluble: Dissolves in water. (aq) b.Insoluble: Does not dissolve in water. (s) c.Salt: Ionic compound.

3.Determining the state of a substance in water. a)If it is not a compound look at the periodic table. b)If it is an ionic compound use a solubility chart. Remember that acids are always soluble, and if a compound is not indicated on this chart, it will be insoluble. If the compound contains both a soluble and insoluble ion, the soluble wins. Predict the state of each compound in the example reactions above Ba(NO 3 ) 2 (aq) + K 2 S (aq)  AgNO 3 + NaCl 

Write the chemical equation for the following reactions and determine the states of the products. Also decide if each is a precipitation reaction. 1. KNO 3(aq) + BaCl 2 (aq)  2.KOH (aq) + Fe(NO 3 ) 3 (aq)  3.Na 2 SO 4(aq) + Pb(NO 3 ) 2 (aq) 

II.Other Types of Reactions A.Reactions are like a night at the prom. 1.Synthesis: Making a compound from two simpler parts.(A couple dances) A + B  AB O 2 + H 2 O  H 2 O 2 Mg + O 2  Fe + O 2  Iron gets a charge of 3+

2.Single-Replacement Reaction: A single ion replaces one of the ions in a compound. (Someone cuts in on the dance) AB + C  AC + B Mg + LiBr  MgBr 2 + Li CaO + Cl 2  Fe 2 O 3 + Na 

3.Double-Replacement Reaction: The ions of two compound switch. (Partner switch) AB + CD  AD + CB Fe 2 O 3 + MgCl 2  FeCl 3 + MgO MgI 2 + Ni 2 O  NaCl + LiBr 

4.Decomposition Reaction: A compound is broken into simpler parts. (the break-up) AB  A + B H 2 O 2  O 2 + H 2 O MgO  Fe 2 O 3 

5.Combustion Reaction: a hydrocarbon reacts with O 2 to produce H 2 O and CO 2. a.Hydrocarbon: a molecule made of mostly carbon and hydrogen C ? H ? + O 2  CO 2 + H 2 O C 4 H 10 + O 2  CO 2 + H 2 O C 3 H 8 O + O 2  CO 2 + H 2 O CH 4 + O 2  H 2 O + CO 2

6.Acid-Base Reaction: A reaction between an acid and a base that produces H 2 O and a salt. (type of Double-Replacement) a.Acid: produces H + ions when in water. b.Base: Produces OH - ions when in water. HA + BOH  H 2 O + BA HCl + NaOH  NaCl + H 2 O H 2 SO 4 + Ca(OH) 2  LiOH + H 3 PO 4 

7.Oxidation-Reduction Reactions (Redox): Involve a transfer of an electron. (something becoming an ion) a)An atom will be alone on one side of the equation, and part of a compound on the other side of the equation. Na + Cl 2  NaCl Mg + LiBr  MgBr 2 + Li H 2 O 2  O 2 + H 2 O

B.Determining types of reactions. 1.Write the balanced equation for the reaction. 2.Determine the state of each of the products. 3.Each reaction will be only one of the following. a.Synthesis, Decomposition, Single-Replacement, Double- Replacement, Combustion. 4.Check to see if the reaction is a precipitation reaction. 5.Check to see if the reaction is a Redox reaction. 6.Check to see if the reaction is an acid-base reaction.

Balance and determine the reaction type(s) MgI 2 + Ni 2 O  NiI + MgO Double Replacement Precipitation

Balance and determine the reaction type(s) C 4 H 10 + O 2  CO 2 + H 2 O Combustion Redox

Balance and determine the reaction type(s) H 2 SO 4 + Ca(OH) 2  CaSO 4 + H 2 O Acid Base Double Replacement

Balance and determine the reaction type(s) Fe 2 O 3 + Na  Fe + Na 2 O Single Replacement Redox Precipitation

Balance, show the states of matter, and classify the reaction Hydrochloric acid reacts with silver nitrate HCl + AgNO 3  HNO 3 + AgCl

Balance, show the states of matter, and classify the reaction Hydrobromic acid reacts with aluminum hydroxide HBr + Al(OH) 3  H 2 O + AlBr 3

Balance, show the states of matter, and classify the reaction Hydrogen peroxide (H 2 O 2 ) is heated and breaks into water and oxygen gas. H 2 O 2  H 2 O + O 2

Balance, show the states of matter, and classify the reaction Liquid propanol (C 3 H 8 O) reacts with oxygen gas. C 3 H 8 O + O 2  CO 2 + H 2 O

Balance, show the states of matter, and classify the reaction Dinitrogen tetrahydride reacts with oxygen to produce nitrogen gas and water.