Crystalline iron(III) nitrate nonahydrate, Fe ( NO ₃ )₃ 9 H ₂ O , has a very pale violet colour. When added to water, the crystals dissolve to form a brown solution. Treatment of this brown solution with concentrated nitric acid yields a very pale violet solution while treatment with HCl yields a yellow solution. Identify the correct statements regarding the above observations.

Options

1. AThe brown colour is due to [ Fe ( OH ) ( H ₂ O )₅ ]²⁺, [ Fe ( OH )₂ ( H ₂ O )₄ ]⁺
2. BViolet colour is due to [ Fe ( H ₂ O )₆ ]³⁺ and yellow colour due to [ FeCl ₄ ]⁻
3. CAddition of HNO ₃ shifts the equilibrium [ Fe ( H ₂ O )₆ ]³⁺+ H ₂ O [ Fe ( OH ) ( H ₂ O )₅ ]²⁺+ H ₃ O ⁺ to lef
4. DAddition of HNO ₃ shifts the equilibrium [ Fe ( H ₂ O )₆ ]³⁺+ H ₂ O [ Fe ( OH ) ( H ₂ O )₅ ]²⁺+ H ₃ O ⁺ to rig