Chapter 9 section 3

Reactions in Aqueous Solutions

Main Idea:

Double–replacement RXNs occur between substances in aqueous solutions and produce precipitates, water, or gas.

Aqueous Solutions:Contain one or more substances called solutes

dissolved in the water. (water being the solvent.)Some molecular compounds like sucrose (table

sugar) and ethanol (grain alcohol) can exist as molecules in solvent.

When ionic compounds dissolve in water their ions can separate through the process of dissociation.

draw an illustration for this ionic reaction2NaOH(aq) + CuCl2 (aq) 2NaCl (aq) + Cu (OH)2

(s)Bonus: name this type of reaction.

Ionic equations:These equations differ from chemical equations in that they show that substances are ions in a solution.

The previous equation becomes:2Na+(aq) + 2OH-(aq) + Cu2+(aq)+ 2Cl- (aq) 2Na+ (aq)+ 2Cl- (aq) + Cu (OH)2 (s) on page 301 in your book.

this is an example of a COMPLETE IONIC EQUATION.

2Na+(aq) + 2OH-(aq) + Cu2+(aq)+ 2Cl- (aq) 2Na+ (aq)+ 2Cl- (aq) + Cu (OH)2 (s)

Note that the sodium and chlorine ions do not participate and are simply present in both the reactants and products, this makes them Spectator ions.

Net ionic equations: only include the particle involved in the RNX.

2OH-(aq) + Cu2+(aq) Cu (OH)2 (s)

Practice problems on page 302 # 35-38

RXNs that produce waterremember some double replacement rxns produce

water as a product.example

HBr (aq) + NaOH (aq) H2O (l) + NaBr(aq)

H+(aq) + Br- (aq) + Na+ (aq) + OH- (aq) H2O (l) + Na+ (aq) + Br- (aq)

H+(aq) +OH- (aq) H2O (l)

Practice Problems on page 304 #s 40-44

RXNs that form a gasother double-replacement reactions form a gas as

a product.common gases produced are carbon dioxide,

hydrogen cyanide, and hydrogen sulfideexample:HCL(aq) +NaHCO3(aq) H2CO3(aq) + NaCl(aq)

H2CO3(aq) H2O (l) + CO2(g)this is why when vinegar (a weak acid) is combined

with baking soda (H2CO3) bubble and fizz for great volcanoes, due to the massive release of CO2(g)

Practice problems on page 306 #s 45-49

Overall equationssee the example in your book on page 307.Homework:

Part1- Write about and describe the “activities” and “travels” of a hydrogen atom during the following reaction and processes: a gaseous hydrogen molecule reacts with a gaseous iodine molecule to form gaseous hydrogen iodide; gaseous hydrogen iodide dissolves in water to form hydroiodic acid; hydroiodic acid reacts with aqueous lithium sulfide to form hydrogen sulfide gas.

Part 2- Complete the 9.3 study guide worksheet Part 3- Turn in all practice problems from this

chapter.Review all practice problems and vocabulary for

your quiz.