Replacement reactions, also known as single displacement reactions, follow a simple rule:
A more reactive element will displace a less reactive element from its compound.
Here's how it works:
1. Reactants: You start with an element (A) and a compound (BC).
2. Reactivity: The element (A) must be more reactive than the element (B) in the compound.
3. Displacement: The more reactive element (A) will replace the less reactive element (B) in the compound.
4. Products: This results in a new element (B) and a new compound (AC).
General Formula:
A + BC → AC + B
Key Points:
* Reactivity Series: The reactivity of elements is determined by their ability to lose electrons. A reactivity series lists elements in order of decreasing reactivity.
* Predicting Products: You can use the reactivity series to predict the products of a replacement reaction.
* Not All Reactions Occur: Not all elements will displace others from their compounds. For example, copper (Cu) is less reactive than silver (Ag), so copper will not displace silver from its compound.
Examples:
* Zinc reacting with hydrochloric acid: Zn + 2HCl → ZnCl2 + H2 (Zinc is more reactive than hydrogen and displaces it from hydrochloric acid)
* Iron reacting with copper sulfate: Fe + CuSO4 → FeSO4 + Cu (Iron is more reactive than copper and displaces it from copper sulfate)
Remember: This rule applies to both metals and nonmetals. However, the reactivity series for metals and nonmetals is different.
