(l9) types of chem. reactions

Types of Chemical Reactions

Chemical Reactions

A reaction takes place if the following indications are observed:

1. Gases are produced2. Precipitates are formed3. Color changes4. Formation of distinct odor

Combination Reaction

Two or more substances react to form a single product.

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Combination Reactions Combination reactions occur when two

or more substances combine to form a compound.

There are three basic types of combination reactions.

1. Two elements react to form a new compound2. An element and a compound react to form

one new compound3. Two compounds react to form one compound

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Combination Reactions

1. Element + Element CompoundA. Metal + Nonmetal Binary Ionic Compound

sg2s NaCl 2ClNa 2

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sg2s MgO 2OMg 2

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s32s AlBr 2 Br3Al 2

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1. Element + Element CompoundB. Nonmetal + Nonmetal Covalent Binary

Compound

s104g2s4 O PO 5P

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Compound

3g2s4 PCl4 Cl 6P

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Compound• Can control which product is made with

the reaction conditions.

chlorine limitedin

AsCl 2 Cl 3As 2 s3g2s

chlorine excessin

AsCl 2 Cl 5As 2 s5g2s

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Compound• Can control which product is made with

the reaction conditions.

fluorine limitedin

SeF F 2Se s4g2s

fluorine excessin

SeF F 3Se g6g2s

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2. Compound + Element Compound

s5g2s3 AsClClAsCl

g6g2s4 SFFSF

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The reaction of oxygen with oxides of nonmetals is an example of this type of combination reaction.

g3 &catalyst

g2g2 SO 2OSO 2

g2g2g COOCO

104264 OPO 2OP

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3. Compound + Compound Compound gaseous ammonia and hydrogen

chloride

lithium oxide and sulfur dioxide

s4gg3 ClNH HClNH

3222 SO LiSOOLi

Decomposition Reaction

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Decomposition Reactions Decomposition reactions occur

when one compound decomposes to form:

1. Two elements2. One or more elements and one or

more compounds3. Two or more compounds

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Decomposition Reactions

1. Compound Element + Element decomposition of dinitrogen oxide

decomposition of calcium chloride

g2g2g2 ON 2ON 2

g2yelectricit

2 ClCaCaCl

2sh

s BAg 2AgBr 2 r

decomposition of silver halides

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2. Compound One Element + Compound(s)

decomposition of hydrogen peroxide

g22or Mn or Feνh

aq22 OO H2O H23

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3. Compound Compound + Compound

decomposition of ammonium hydrogen carbonate g2g2g3s34 COO HNHHCONH

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Displacement Reactions Displacement reactions occur

when one element displaces another element from a compound. These are redox reactions in which the

more active metal displaces the less active metal of hydrogen from a compound in aqueous solution.

Activity series is given in Table 4-14.

Displacement Reactions

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Displacement Reactions1. [More Active Metal + Salt of Less Active Metal]

[Less Active Metal + Salt of More Active Metal] molecular equation

(s)aq3(s) aq3 Ag CuNO Cu +AgNO

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Displacement Reactions Total ionic equation

You do it!

Net ionic equationYou do it!

(s)-

aq3aqs-

aq3aq Ag NO+CuCu +NO+ Ag

(s)aq(s)aq Ag Cu Cu +Ag

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Displacement Reactions2. [Active Metal + Nonoxidizing Acid] [Hydrogen +

Salt of Acid] Common method for preparing hydrogen in the laboratory. HNO3 is an oxidizing acid.

Molecular equation

g2aq342aq42(s) H 3 + )(SOAl SO3H + Al 2

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Displacement Reactions Total ionic equation

You do it!

Net ionic equationYou do it!

g2-2aq4

3aq

-2aq4aq(s) H 3 + SO 3 + Al 2 SO 3+H 6 + Al 2

g23aqaq(s) H 3 +Al 2 H 6 + Al 2

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Displacement Reactions The following metals are active

enough to displace hydrogen K, Ca, Na, Mg, Al, Zn, Fe, Sn, & Pb

Notice how the reaction changes with an oxidizing acid. Reaction of Cu with HNO3.

• H2 is no longer produced.

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Displacement Reactions3. [Active Nonmetal + Salt of Less Active Nonmetal]

[Less Active Nonmetal + Salt of More Active Nonmetal]

Molecular equation

(aq)s2aqg2 NaCl 2 I NaI 2 + Cl Total ionic equation

You do it!

-aqaqs2

-aqaqg2 Cl 2 +Na 2 I I 2 + Na 2 +Cl

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Displacement Reactions Net ionic equation

You do it!

-aqs2

-aqg2 Cl 2 I I 2 +Cl

Double Displacement Reactions

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Metathesis Reactions Metathesis reactions occur when two

ionic aqueous solutions are mixed and the ions switch partners.

AX + BY AY + BX Metathesis reactions remove ions from

solution in two ways:1. form predominantly unionized molecules like

H2O2. form an insoluble solid

Ion removal is the driving force of metathesis reactions.

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Metathesis Reactions

1. Acid-Base (neutralization) Reactions Formation of the nonelectrolyte H2O acid + base salt + water

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Metathesis Reactions Molecular equation

)(2 (aq)(aq)(aq) OH + KBr KOH + HBr Total ionic equation

You do it!

)(2-aqaq

-aqaq

-aqaq OH + Br+KOH+K+Br+H

Net ionic equation

You do it!

)(2-aqaq OH OH +H

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Metathesis Reactions

2. Precipitation reactions are metathesis reactions in which an insoluble compound is formed.

The solid precipitates out of the solution much like rain or snow precipitates out of the air.

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Metathesis Reactions Precipitation Reactions Molecular equation

(s)3)aq(3aq)(32(aq)23 CaCO +KNO 2 COK + )Ca(NO Total ionic reaction

You do it!

s3-

aq3aq

-2aq3aq

-aq3

2aq

CaCO NO 2K 2

COK 2 NO 2 Ca

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Metathesis Reactions Net ionic reaction

You do it!

(s)3-2aq3

2aq CaCO CO +Ca

(l9) types of chem. reactions

Technology

compound element

redox reactions

double displacement

new compound

bx metathesis reactions

types of chemical reactions

active metal of hydrogen

type of combination