TYPES OF REACTIONS

A. Direct Combination:               A + B       ® AB

       S (s) + O₂(g)       ® SO₂ (g)
HCl (g) + NH₃ (g) ® NH₄Cl (s)

B.       Decomposition:   AB ® A + B

       2 KClO₃ (s) ® 2 KCl (s)+ O₂ (g)

C.       Single-Replacement:  A + BC ® AC + B

       Zn (s)+ HCl (aq) ® ZnCl₂ (aq) + H₂(g)
Cu (s) + 2 AgNO₃(aq) ® Cu(NO₃)₂(aq) + 2 Ag(s)

D. Double-Replacement : AB + CD ® AD + CB

       BaCl₂ (aq)+ Na₂SO₄ (aq) ® 2 NaCl (aq) + BaSO₄ (s)

E. Combustion :   C_xH_y + O₂ ® xCO₂ + y/2H₂O

       C₃H₈(g) + 5 O₂(g) ® 3 CO₂(g) + 4 H₂O(l)