XXII. Decomposition (AB →A + B)- A sample of calcium carbonate is heated:
CaCO 3 →CaO + CO 2 - Hydrogen peroxide is gently warmed:
H 2 O 2 →H 2 O + O 2 - Manganese dioxide (acting as a catalyst) is added to a solid sample of potassium
chlorate and the mixture is then heated:
KClO 32 MnO^2 KCl O+ - Solid aluminum hydroxide is heated:
Al(OH) 3 →Al 2 O 3 + H 2 O
XXIII. Single Displacement (A + BC →AC + B) - Chlorine gas is bubbled through a strong solution of potassium bromide:
Cl 2 + Br–→Cl–+ Br 2
Note: This is also a redox reaction.
- Powdered lead is added to a warm solution of copper(II) sulfate:
Pb Cu++^2 +2SO 4 - "PbSO 4 +Cu - Strontium turnings are added to a 4 M sulfuric acid solution:
Sr H+++2SO 4 - "SrSO 42 +H - Silver is added to a solution of hot hydrochloric acid:
Ag + H++ Cl–→AgCl + H 2
XXIV. Complex Ions* - A concentrated solution of ammonia is added to a solution of zinc nitrate:
Zn^2 +NH 33 "Zn NH^h 42 +
or
Zn^2 +++NH 32 H O"Zn^hOH 2 +NH 4 +
The concentration of NH 3 determines the product. - A solution of iron(III) iodide is added to a solution of ammonium thiocyanate:
Fe^3 ++SCN-"Fe SCN^h 6 3- - A solution of copper(II) nitrate is added to a strong solution of ammonia:
Cu^2 ++NH 33 "Cu NH^h 42 + - A concentrated potassium hydroxide solution is added to solid aluminum hydroxide:
OH-+Al OH^^hh 34 "Al OH -
*Ligands are generally electron pair donors (Lewis bases). Important ligands are NH 3 , CN–, and OH–. Ligands bond to a central
atom that is usually the positive ion of a transition metal, forming complex ions and coordination compounds. On the AP exam,
the number of ligands attached to a central metal ion is often twice the oxidation number of the central metal ion.
Writing and Predicting Chemical Reactions