I completely understand Le Chateliers principle but I have no idea about these questions. They're due tomorrow so fast help would be appreciated.
Why did adding water to the equilibrium involving CoCl_4_^2-^ cause the color to change?
Use Le Chateliers principle to explain the different colors found in the following equilibria. Show all chemical reactions.
My results were that it turned orange before HCl, yellow after NaOH, and pink after HCl.
How does Le Chateliers principle explain the result you obtained when you added HCl to a suspension of Ca(OH)_2_ in water?
How does Le Chateliers principle explain the result you obtained after the addition of NaOH?
Thank you!
To understand and answer these questions using Le Chatelier's principle, let's break down each scenario:
1. Why did adding water to the equilibrium involving CoCl4^2- cause the color to change?
When water is added to the equilibrium involving CoCl4^2-, it affects the concentration of reactants and products. The equilibrium can be represented by the following equation:
CoCl4^2- (aq) ⇌ Co(H2O)6^2+ (aq) + 4 Cl^- (aq)
The addition of water on the left-hand side of the equation decreases the concentration of CoCl4^2- ions. According to Le Chatelier's principle, the system will try to counteract the decrease. It will shift the equilibrium to the right to produce more CoCl4^2- ions.
As a result, the concentration of Co(H2O)6^2+ ions increases, leading to a change in color. Co(H2O)6^2+ ions have a pink color, which is why the solution changes color when water is added.
2. How does Le Chatelier's principle explain the result obtained when adding HCl to a suspension of Ca(OH)2 in water?
When HCl is added to a suspension of Ca(OH)2 in water, an acid-base reaction occurs. The equilibrium can be represented as:
Ca(OH)2 (s) + 2 HCl (aq) ⇌ CaCl2 (aq) + 2 H2O (l)
Adding HCl on the right-hand side of the equation increases the concentration of HCl and Cl^- ions. According to Le Chatelier's principle, the system will try to counteract this increase. It will shift the equilibrium to the left to consume the excess HCl and Cl^- ions.
As a result, more Ca(OH)2 will dissociate to replenish the OH^- ions consumed by the added acid. This reaction produces CaCl2, which is a colorless solution. Therefore, the result obtained after the addition of HCl is a colorless solution.
3. How does Le Chatelier's principle explain the result obtained after the addition of NaOH?
When NaOH is added, it dissociates into Na+ and OH^- ions. The equilibrium can be represented as:
HCl (aq) + NaOH (aq) ⇌ NaCl (aq) + H2O (l)
Adding NaOH on the right-hand side increases the concentration of OH^- ions. According to Le Chatelier's principle, the system will try to counteract this increase. It will shift the equilibrium to the left to consume the excess OH^- ions.
As a result, more HCl will react with the additional OH^- ions to form water molecules. This reaction decreases the concentration of HCl and increases the concentration of NaCl. NaCl is a colorless solution, leading to a color change after the addition of NaOH.
These explanations showcase how Le Chatelier's principle can be applied to understand the shifts in equilibrium and the resulting color changes in chemical reactions.