Chemical Equilibrium and Reaction Effects

The video explains L's principle, which states that a reaction equilibrium will shift to relieve applied stress. Through various experiments, the video demonstrates how adding different substances like iron nitrate, potassium thiocyanate, sodium hydroxide, potassium chloride, silver nitrate, and mercury nitrate affects the equilibrium of a reaction involving iron and thiocyanate ions. The shifts in equilibrium are observed through changes in color and the formation of precipitates, illustrating the principle in action.

What does L's principle suggest about a reaction at equilibrium when stress is applied?

• The reaction will slow down.

• The reaction will speed up.

• The reaction will shift to relieve the stress.

• The reaction will stop.

What happens to the color of the solution when iron(III) nitrate is added?

• It turns blue.

• It becomes colorless.

• It turns a darker red.

• It turns green.

How does the addition of potassium thiocyanate affect the reaction?

• The reaction becomes colorless.

• The reaction stops.

• The reaction shifts in the forward direction.

• The reaction shifts in the reverse direction.

What is the effect of adding sodium hydroxide to the reaction mixture?

• The red color intensifies.

• The red color disappears completely.

• The solution turns blue.

• The red color decreases significantly.

What happens when potassium chloride is added to the solution?

• The color intensity increases.

• The color intensity decreases.

• The solution turns green.

• The solution becomes colorless.

What is observed when silver nitrate is added to the reaction mixture?

• The solution turns blue.

• The red color disappears and a white solid forms.

• The red color intensifies.

• The solution becomes colorless.

What does the formation of a white solid indicate when silver nitrate is added?

• Formation of a new complex ion.

• Precipitation of iron ions.

• Formation of slightly soluble silver thiocyanate.

• Complete dissolution of reactants.

How does the addition of mercury(II) nitrate affect the reaction equilibrium?

• The reaction stops completely.

• The equilibrium shifts in the reverse direction.

• The equilibrium remains unchanged.

• The equilibrium shifts forward.

What is the role of mercury(II) ions in the reaction?

• They precipitate out of the solution.

• They have no effect on the reaction.

• They form a new complex ion with thiocyanate.

• They increase the concentration of iron ions.

What is the overall effect of adding different ions to the reaction mixture?

• The reaction always shifts forward.

• The reaction always shifts in reverse.

• The reaction shifts to relieve the stress applied by the added ions.

• The reaction becomes colorless.