Final answer:
To balance the equation for the reaction between FeCl₃ and KSCN, one places a 1 in front of FeCl₃ and Fe(SCN)₃ to balance iron (Fe), a 3 in front of KSCN to balance the SCN ions, and a 3 in front of KCl to balance the potassium (K) and chlorine (Cl) atoms.
Step-by-step explanation:
The equation to balance is:
__ FeCl₃(aq) + __ KSCN(aq) → __ Fe(SCN)₃(aq) + __ KCl(aq)
To balance this chemical equation, we need to ensure that the number of atoms of each element on the reactant side is equal to the number of atoms of that element on the product side.
Looking at the equation, we can see that we have 1 Fe on both sides, so we can start by placing a 1 in front of FeCl₃ and Fe(SCN)₃ to balance the iron atoms. Next, for each formula unit of Fe(SCN)₃, we require 3 SCN- ions, so we will need 3 KSCN to provide those. This also gives us 3 K+ ions. Therefore, we need to place a 3 in front of KSCN. Finally, since we have 3 Cl₃- from the FeCl₃ and also need to have 3 K+ ions to pair with them, we put a 3 in front of KCl.
The fully balanced equation is:
1 FeCl₃(aq) + 3 KSCN(aq) → 1 Fe(SCN)₃(aq) + 3 KCl(aq)