Chemical Equilibrium Lab Report

Complex Ion Equilibrium

Acid Base Equilibrium

Here is a closer look of the test tube

1) A saturated solution is when no more solute can be dissolved into the solution. On a microscopic level, the solute is being dissolved into the solution and the dissolved solute is being formed. Since the human eye cannot not see any changes, the forward and reverse reactions are equal and equilibrium exists.

2) When 1mol/L of HCl is added, the equilibrium shifts slightly to favor the reactants, however the stress is relieved and equilibrium is established. When 11.7mol/L of HCl is added, the large concentration of Cl ions caused a large shift in equilibrium to favor the reactants causing NaCl to form in visible amounts

3) The Ag ions bond with the SCN molecule causing a shift in equilibrium to favor the reactants. This causes the concentration of FeSCN to decrease as the system attempts to alleviate the stress by producing more reactants. However the stress is enough to remove the equilibrium resulting in the complete replacement of red with white in the solution

The HCl breaks down into H+ and Cl-, the H+ bonded with the OH- to form water and the Cl- reacted with itself to create Cl2. The OH- is taken away and the system attempts to reestablish equlibrium be creating more. However, the system does not reestablish equilibrium and no more OH- is produced, hence the color change from pink to clear.

Chemical Equilibrium Lab Report

By: Vivian & Christine

Step 2) several small crystals of ammonium chloride is added into the first test tube.

Questions

The solution changed from a pink color to clear

Step 1) 5 mL of the pink dilute solution is added into three test tubes.

Step 1) Added 10 drops of 11.7mol/L of HCL to saturated NaCl solution

Step 1) 5 mL of the red complex ion solution [FeNCS2+] was poured into 4 test tubes. The first test tube is used to compare color with what will be happening in the other test tubes

Fe3+ + SCN- <---> [FeNSC2+]

Acid/Base Equilibrium Analysis

Analysis

Stress: addition of ammonia chloride crystals:

The ammonia chloride breaks into its ions. The concentration of NH4 increases and the equilibrium shifts to the left (reactant side). As a result, the solution becomes colorless due to the less amount of OH being produced and it becomes less basic.

Stress: addition of HCl:

When HCl breaks into its ions hydrogen is present which increases the acidity of the solution. As a result, equilibrium shifts to the right (products side) and the solution becomes colorless. Hydrogen gas is also formed.

Stress: addition of NH4OH:

The solution had undergone no color change and remains pink

Adding HCl formed small amounts of solid NaCl causing the new solution to formed crystals and precipitate out of the solution.

Solubility Equilibrium

Step 2) Added 10 drops of 1.0mol/L of HCl to the second test tube of saturated NaCl solution

A diluted ammonia solution is prepared by adding four drops of 14.8 mol/L NH4OH to 100mL of distilled water. 10 drops of phenolphthalein indicator is also added to turn the solution into pink.

NH3 + H2O <---> NH4 + OH-

Step 3) one dropper full of 0.10 mol/L KSCN solution is added to the third test tube

5.0 mL of saturated sodium chloride solution in 2 test tubes.

NaCl(s) <----> Na+ (aq) + Cl- (aq)

There was no change when HCl was added.

As the droplet of KSCN enters the solution, it slowly mixes in with the complex solution and it is a darker red.

Step 4) one drop of 14.8 mol/L NH4OH is added into the third test tube

Analysis for Solubility Equilibrium

There was no change in color when 1 drop is added into the solution. But when an additional drop was added it slightly got more pink.

Part a)

The HCl breaks down into hydrogen and chlorine ions causing an increase in concentration of chlorine. This increase causes equilibrium to shift to the left (reactant side). As a result, NaCl(s) increases and a precipitate forms.

Complex Ion Equilibrium

Part b)

The HCl breaks down into its ions, one that is hydrogen. The increase of the hydrogen concentration increases the acidity of the solution causing a decrease in OH concentration. This decrease causes equilibrium to shift to the right (product side). As a result, more of the aqueous solution is formed.

Part B: saturated iron (III) hydroxide solution

Analysis for Complex Ion Equilibrium

Adding 1.00mol/L of HCl to Fe(OH)3 solution caused the solution to separate

Step 2) one dropper full of 0.10mol/L FeCl3 was added to the second test tube of red complex ion solution

Stress 1: FeCl3 breaks down into its ions causing an increase in Fe concentration. This causes equilibrium to shift to the right (product side) and the red color is intensified.

Stress 2: KSCN breaks into its ions and the concentration of SCN increases. The equilibirum shifts to the right (product side) and the solution becomes more red.

Stress 3: The AgNO3 breaks into its ions. Ag and SCN create AgSCN solid precipitate.

1

2 mL of 0.10 mol/L iron (III) chloride solution is combined with 2 mL of 1.00 mol/L NaOH solution.

Fe(OH)3(s) <---> Fe3+(aq) + 3 OH-(aq)

The red complex ion solution turned red

Step 4) added 0.10 mol/L AgNO3 solution (dropwise) until there was change

As AgNO3 is added, the red solution changed into a cloudy white colour.

Step 3) A few drops of 11.7 mol/L HCl is added into the second test tube

The color of the solution also went clear when HCl is added and it also heated up, causing the top of the test tube to fog up