Ngā Whāinga Ako 🔗
- To describe what happens in a displacement reaction.
Mahi Tuatahi 🔗
- Write down the general reaction for a precipitation reaction
- What is a precipitate?
- Write a word equation for a reaction between sodium hydroxide and copper carbonate
- Will a precipitate form during this reaction? (Solubility rules)
Displacement Reactions 🔗
\newline[ \begin{aligned} A + BC \longrightarrow B + AC \end{aligned} \newline]
A reaction where an ion (B) is replaced by another ion (A) in a compound.
Tauria Tahi 🔗
A piece of copper is placed into a solution of silver nitrate. The copper replaces the silver, making copper nitrate and silver.
- Write a word equation
- Write a symbol equation
- copper + silver nitrate $\longrightarrow$ + copper nitrate + silver
- $Cu + AgNO_{3} \longrightarrow Cu(NO_{3})_{2} + Ag$
Precipitation vs. Displacement 🔗
- Precip: $AB + CD \longrightarrow AD + CB$
- Disp: $A + BC \longrightarrow B + AC$
- We can see how one ion is displaced in a displacemenet reaction, but two ions are displaced in a precipitation reaction. This makes precipitation a “double displacement” reaction.
Tauria Rua 🔗
A piece of magnesium is dropped into a copper sulfate solution.
- Write a word equation
- Write a symbol equation
- Include states
- Try to balance it!
Why Does Displacement Occur? 🔗
In humans a couple might break up (be displaced) because one partner has found someone more attractive.
In chemistry, one ion displaces another because it is more reactive.
Activity Series 🔗
Note which end is the most and least reactive on your resource sheet.
\newline[ \begin{aligned} & \text{Most Reactive} \longrightarrow \text{Least Reactive} \newline & Ca, Mg, Al, Zn, Fe, Pb, (H), Cu, Ag \end{aligned} \newline]
Tauria Toru 🔗
- Write a word equation
- Write a symbol equation (with states and balanced)