Question

could you explain LeChatelier's principle

196 4. Saturated NaCI Solution Equation: Nael (s) = Nalag) + c lag); Observations Explanation (Le Chatelier's Principle) HCl(aq) addition Cloudy white mulla 5. Saturated BaCro Solution Equation: Babr Oy (6) z bólag) + Cr Oslag) Observations Explanation (LeChatelier's Principle) (1) BaCl2 + pail KeCrO4 (Aqueous solutions) yellow (2) HCI (aq) addition yellow thema to orang. 6. Thiocyano-Iron(W) Complex modes do Equation: Fe's SCN → [Fe (sen Observations Explanation (LeChatelier's Principle) (1) Fe(NO3)2 (aq) Orange - Brown addition (2) KSCN (aq) addition ark Brown (3) NaOH(aq) addition follow with orange precipitare

Answer 1

Le chatlier principle states that whenever there is a change in equilibrium, the system reacts to these changes in such a manner that the system can attain the equilibrium again.

For example, if the concentration of one of the ion at reactant side is increased, the equilibrium will be disturbed. So, the system will start producing more product to attain the equilibrium. When more of the product is formed, it is said that the equilibrium has shifted in forward direction.

Vice versa will be true when concentration of one of the ion will be increased at product side.

Nach (s) HCl lag) Nau+ He & Na + (aq) + ce cag) 47 (ag) + ce lag) Nat +H+ + all- overall reaction. The concenbration of a ions increases on product side. So, the system will move in backward direction to produce more Nadl (s). Because of this Nace, cloudiness appears. 5. & Baberoy (s) ² Baut (aq) + Cool - Lag - Bay + k, Croy & Bart +20 + 2k + + Croy Baco0y + Ballet ky Co Oy = a Belt + Økt + 20+ DGroot In the above reaction, after addition of Bach, and k croy, the concentration of both Ba²+ and Cror increases on product side. So, the system will move in backward direction to produce more BaGoy Ls), due to which yellow colour appeared

5 b) BaCrO₂ (s) & - Hll (aq) I Ba2+ (aq) + crop laq) Byt Lag) + co (aq) ] X2 BacyOy (8) +2461 (aq) = Bacte (s) + 2H+ + Coog-lay) The concentration of Baat ion on product side decrease because of formation of Bacla. So, the reaction will move in forward direction to produce more Ba²+ ions. Due to this more chromate ions will be produced, which will impart orange color to the solution.

6.

1) When Fe(NO₃)₃ will be added the concentration of Fe³⁺ will increase in the solution. As a result, the reaction will move in forward direction, and the colour of the solution remains blood red.

2) When KSCN will be added the concentration of SCN^- ions will increase in the solution. As a result, the reaction will move in forward direction and the color of the solution remains blood red.

3) When NaOH is added, the Na⁺ ions will react with SCN^- and Fe³⁺ will react with OH^- ions forming NaSCN and Fe(OH)₃ respectively. As a result, the concentration of both Fe³⁺ and SCN^- ions decreases on the reactant side. So, the reaction will move in backward direction and the colour of the solution changes from blood red to orange-yellow.