INORGANIC REACTIONS AND SYNTHESIS
Compounds and Elements react with each other in several ways. Memorizing every kind of reaction would be challenging and also not necessary, because nearly every inorganic chemical reaction goes down into one or more of four broad types.
Types of reactions
1. Combination Reactions
Two or more than two reactants form one result in a combination reaction. An instance of a combination reaction is the formation of sulfur dioxide when sulfur is burned in air:
S (s) + O2 (g) → SO2 (g)
2. Decomposition Reactions
In a decomposition reaction, a compound falls into two or more substances. Decomposition generally results from electrolysis or heating. An instance of a decomposition reaction is the break of mercury (II) oxide into its component elements.
2HgO (s) + heat → 2Hg (l) + O2 (g)
3. Single Displacement Reactions
A single displacement reaction is considered by an ion or atom of a single compound replacing an atom of another element. An instance of a single displacement reaction is the displacement of copper ions in a copper sulfate solution through zinc metal, forming zinc sulfate:
Zn (s) + CuSO4 (aq) → Cu (s) + ZnSO4 (aq)
SYNTHESIS
Several compounds that do not take place naturally or are difficult to get may be synthesized in the laboratory. A specific synthesis may proceed by various individual steps that involve the formation of several intermediate chemical compounds on the way to the final result. A number of these steps do not produce 100% yields and so you obtain fewer products than you would have supposed. Chemists frequently devote a great deal of effort and time investigating the reaction conditions to enhance the final yield. Though, there are even more subtle problems: one's laboratory skills. However if the reaction can be coaxed to provide a 100% yield, if you drop part of it on the way to the balance or do not fully dry it or leave a few of it on a piece of filter paper, you may considerably reduce your final yield.
Today's synthesis starts with an oxidation-reduction reaction where Cu (s) dissolves with the nitric acid to form Cu2+(aq):
3 Cu(s) + 8 HNO3(aq) 3 Cu(NO3)2(aq) + 2 NO(g) + 4 H2O(l)
3 Cu(s) + 8 H+(aq) + 8 NO3-(aq) ? 3 Cu 2+(aq) + 6 NO3-(aq) + 2 NO(g) + 4 H2O(l)
3 Cu(s) + 8 H+(aq) + 2 NO3-(aq) ? 3 Cu 2+(aq) + 2 NO(g) + 4 H2O(l)
The three equations displayed above, depict the balanced chemical equation or formula unit, and net ionic equation and the total ionic equation for the oxidation of Cu(s) to Cu2+(aq) by the NO3-(aq) ion. The solution undergoes various color changes that represent distinct oxidation states of copper. At last, a blue aqueous solution of Cu2+ ions is produced. Simultaneously the reduction of NO3-(aq) ion produced the colorless gas nitrogen monoxide, NO. Though, NO is very reactive and is converted to the orange-brown gas nitrogen dioxide, NO2 as soon as it comes in contact with the O2 in the air. Nitrogen dioxide is similar gas you see over highly polluted urban areas.