ionic equations (1 Viewer)

[sikeveo]

Can someone reaqaint my memory with how to do this:

Write balanced ionic equation fot this reaction. Don't include spectator ions.

Solid strontium carbonate reacts with hydrochloric acid to give carbon dioxide.

 

[Dreamerish*~]

Neutral species

SrCO_3(s) + 2HCl_(aq) → SrCl_2(aq) + H₂O_(l) + CO_2(g)

Ionic

SrCO_3(s) + 2H⁺_(aq) → Sr²⁺_(aq) + H₂O_(l) + CO_2(g)

Spectator ions are those that don't change state. In this case, just Cl.

 

[XcarvengerX]

Write balanced ionic equation fot this reaction. Don't include spectator ions.

This is called net ionic equation.
The ionic equation will include the spectator ions, which in this case is Cl^-.

 

[sikeveo]

how do we know which ones are the spectator ions again?

 

[Riviet]

how do we know which ones are the spectator ions again?

Spectator ions are those that don't change state.

Cl remains aqueous, even though a new compound is formed on the RHS of the equation. Therefore it is a spectator.

 

[XcarvengerX]

how do we know which ones are the spectator ions again?

The ions that do not change before and after the reaction.

In your example, the ionic equation is:
SrCO₃(s) + 2H⁺(aq) + 2Cl^-(aq) → Sr²⁺(aq) + 2Cl^-(aq) + H₂O(l) + CO₂(g)

You see that 2Cl^- is the same on the left (reactant side) and right (product side) which means Cl^- does not participate in the reaction, thus the term spectator ions.