I II III IV V

Ch. 8 – Chemical Reactions

III. Types of Chemical Reactions

(p. 256 - 267)

A. Combustion

CH4(g) + 2O2(g) CO2(g) + 2H2O(g)

the burning of any substance in O2 to produce heat

A + O2 B

Na(s)+ O2(g)

C3H8(g)+ O2(g) 5 3 4

A. Combustion

Products: contain oxygen hydrocarbons form CO2 + H2O

CO2(g)+ H2O(g)

Na2O(s) 4 2

B. Synthesis

the combination of 2 or more substances to form a compound

only one product

A + B AB

B. Synthesis

H2(g) + Cl2(g) 2 HCl(g)

Al(s)+ Cl2(g) AlCl3(s)2 3 2

B. Synthesis

Products: ionic - cancel charges covalent - hard to tell

C. Decomposition

a compound breaks down into 2 or more simpler substances

only one reactant

AB A + B

C. Decomposition

2 H2O(l) 2 H2(g) + O2(g)

KBr(l) K(s) + Br2(l) 2 2

C. Decomposition

Products: binary - break into elements others - hard to tell

D. Single Displacement

one element displaces another in a compound metal displaces metal (+) nonmetal displaces nonmetal (-)

A + BC B + AC

D. Single Displacement

Cu(s) + 2AgNO3(aq) Cu(NO3)2(aq) + 2Ag(s)

Fe(s)+ CuSO4(aq) Cu(s)+ FeSO4(aq)

D. Single Displacement

Products: metal metal (+) nonmetal nonmetal (-) free element must be more active (check activity series)

Br2(l)+ NaCl(aq) N.R.

AB + CD AD + CB

E. Double Displacement

ions in two compounds “change partners” cation of one compound combines with

anion of the other

E. Double Displacement

Pb(NO3)2(aq) + K2CrO4(aq) PbCrO4(s) + 2KNO3(aq)

Pb(NO3)2(aq)+ KI(aq) PbI2(s)+ KNO3(aq)

E. Double Displacement

Products: switch negative ions one product must be insoluble (check

solubility table)

NaNO3(aq)+ KI(aq) N.R.

2 2

Practice Problems:

1. Li(s) + N2(g) Synthesis

6Li(s) + N2(g) 2Li3N (aq)

2. Mg(s) + CrCl3(aq) Single Displacement

3Mg(s) + 2CrCl3(aq) 3MgCl2 (aq) + 2Cr(s)

NO REACTION!!

Practice Problems:

3. CoBr2(s)

Decomposition

CoBr2(s) Co(s) + Br2(l)

4. C4H8(g) + O2(g)

Combustion

C4H8(g) + 6O2(g) 4CO2(g) + 4H2O(g)

Practice Problems:

5. KBr(aq) + AgNO3(aq)

Double Displacement

KBr(aq) + AgNO3(aq) KNO3(aq) + AgBr(s)

6. NiI2(aq) + FeSO4(aq)

Double Displacement

NiI2(aq) + FeSO4(aq)NiSO4 (aq) + FeI2 (aq)

NO REACTION!!

Time for a WS, then a lab!

Predicting Products WS Predicting Products Lab