Chemical ReactionsChemical Reactions

Predicting Products and Balancing Predicting Products and Balancing EquationsEquations

I. Synthesis (Composition) I. Synthesis (Composition) Reactions Reactions

A) Liquid hydrogen A) Liquid hydrogen plus liquid oxygen plus liquid oxygen yields gaseous water yields gaseous water plus a lot of energy. plus a lot of energy.

HH2(l) 2(l) + O+ O2(l) 2(l) --> H--> H22O O (g)(g)

reactants yield reactants yield productsproducts

2H2H2(l) 2(l) + O+ O2(l) 2(l) --> 2H--> 2H22O O (g)(g)

Coefficients are used Coefficients are used to balance equations.to balance equations.

B. All these type reactions B. All these type reactions take the general formtake the general form

A + B --> ABA + B --> AB

Two or more elementsTwo or more elements

yielding a singleyielding a single

compound.compound.C. FeC. Fe(s) (s) + O+ O2 (g) 2 (g) --> FeO--> FeO2 (s)2 (s)

Iron plus oxygen yields Iron plus oxygen yields iron IV oxide (rust).iron IV oxide (rust).

II. Decomposition ReactionsII. Decomposition Reactions

All take the general formAll take the general form

A B ---> A + BA B ---> A + B2KClO2KClO3(s) 3(s) -->2KCl-->2KCl(s)(s) + O + O2(g2(g

This reaction was one of This reaction was one of the first reactions used to the first reactions used to make pure oxygen. make pure oxygen.

Salt producing ions in Salt producing ions in water is another example.water is another example.

2NaCl2NaCl(s) (s) -->2Na-->2Na(aq)(aq) + Cl + Cl2(aq)2(aq)

III. Single Replacement ReactionsIII. Single Replacement Reactions

A. These take the form of A. These take the form of

+ +- +- ++ +- +- +

A + BC -> AC + BA + BC -> AC + B

ZnZn(s) (s) + 2HCl+ 2HCl(aq)(aq) ---> ---> ZnClZnCl2S) 2S) + H+ H2(g)2(g)

This is one of the This is one of the reactions we used in reactions we used in the lab to make the lab to make hydrogen.hydrogen.

B. They may also take the B. They may also take the formform

- +- +- -- +- +- -

C + AD --> AC + DC + AD --> AC + DFF2(g) 2(g) + 2 KI+ 2 KI(s) ---->(s) ---->

2KF2KF(s) (s) + I+ I2(g)2(g)

IV. Double Replacement IV. Double Replacement ReactionsReactions

Take the general form Take the general form

+ - + - + - + -+ - + - + - + -

AB + CD --> AD + CBAB + CD --> AD + CB

HClHCl(aq) (aq) + NaOH+ NaOH(aq) (aq) -->-->

acid base acid base NaClNaCl(s)(s) + HOH + HOH(l)(l)

salt watersalt water

Neutralization rxn (also how Neutralization rxn (also how soap is made)soap is made)

V. Combustion ReactionV. Combustion Reaction

Take the general form of Take the general form of

CCxxHHy y + O+ O2 2 --> CO--> CO2 2 + H+ H22OO

(excess)(excess)

CCxxHHy y + O+ O2 2 --> CO--> CO + H+ H22OO

(limited)(limited)

Any hydrocarbon when Any hydrocarbon when

burned produces carbonburned produces carbon

dioxide and waterdioxide and water

(gasoline and natural(gasoline and natural

gas are other examples)gas are other examples)