Ferric-Thiocyanate Equilibrium

Interactive Simulation of Le Chatelier's Principle

Reaction: $Fe^{3+}_{(aq)} + SCN^-_{(aq)} \rightleftharpoons [Fe(SCN)]^{2+}_{(aq)}$
ChemAI Logo
📖 Lab Manual: Aim, Principle & Procedure
▼

1. Aim

To study the shift in equilibrium between Ferric ions ($Fe^{3+}$) and Thiocyanate ions ($SCN^-$) by increasing or decreasing the concentration of either of the ions.

2. Principle

When Ferric Chloride ($FeCl_3$) reacts with Potassium Thiocyanate ($KSCN$), a reversible reaction occurs:

$Fe^{3+}_{(aq)} + SCN^-_{(aq)} \rightleftharpoons [Fe(SCN)]^{2+}_{(aq)}$
(Yellow) + (Colorless) $\rightleftharpoons$ (Deep Red)

Le Chatelier's Principle: If concentration of reactants ($Fe^{3+}$ or $SCN^-$) is increased, equilibrium shifts Right. If decreased, equilibrium shifts Left.

3. Materials

  • $0.1M$ Ferric Chloride ($FeCl_3$)
  • $0.1M$ Potassium Thiocyanate ($KSCN$)
  • Solid Oxalic Acid ($H_2C_2O_4$)
  • Reference Color Control (Tube A)

4. Procedure

  1. Tube A: Control tube (Do not alter).
  2. Tube B: Add $FeCl_3$ to increase $[Fe^{3+}]$.
  3. Tube C: Add $KSCN$ to increase $[SCN^-]$.
  4. Tube D: Add Oxalic Acid to decrease $[Fe^{3+}]$. (Oxalic acid forms a stable complex $[Fe(C_2O_4)_3]^{3-}$, removing $Fe^{3+}$ from the equilibrium).

🧪 Reagents Bench

$FeCl_3$
$KSCN$
Oxalic Acid
Select a reagent to add to a test tube
A
B
C
D

📝 Observations Log

Tube Color Change Shift
A Deep Red Reference
B - -
C - -
D - -

Equilibrium Inference

Select a reagent and add it to a tube to observe Le Chatelier's Principle in action.
Reagent added!