The first one is Synthesis.
A synthesis reaction is when two or more simple compounds combine to form a more complicated one. These reactions come in the general form of:
A + B ---> AB
One example of a synthesis reaction is the combination of iron and sulfur to form iron (II) sulfide:
8 Fe + S8 ---> 8 FeS
The second reaction is Decomposition.
A decomposition reaction is the opposite of a synthesis reaction - a complex molecule breaks down to make simpler ones. These reactions come in the general form:
AB ---> A + B
One example of a decomposition reaction is the electrolysis of water to make oxygen and hydrogen gas:
2 H2O ---> 2 H2 + O2
The last one (for now) is Single Replacement.
This is when one element trades places with another element in a compound. These reactions come in the general form of:
A + BC ---> AC + B
One example of a Single Resplacement reaction is when magnesium replaces hydrogen in water to make magnesium hydroxide and hydrogen gas:
Mg + 2 H2O ---> Mg(OH)2 + H2
We also learned how to tell if a single-replacement reaction would actually take place or not depending on the reactivity of the metal/nonmetal that's being reacted with:
If the metal/nonmetal is less reactive then no reaction takes place. for example;
Mg + Cu(NO3)2 ---> Mg(NO3)2 + Cu
- This equation DOES take place since Magnesium is more reactive than Copper
2KI + 1Cl2 ---> 2KCl + 1I2
- Same thing can be done with non-metals. Single replacement of non-metals.
