Write a one or two paragraphs of
-what was study in Introduction to Equilibrium Le Chateliers Principle
-Summarize what happened in these results shown below
-what results did this experiment end up with whether this lab was successful or not
Reaction 1 K₂CrO₄ (yellow), NaOH (colorless) HCl (colorless) |
The solution changed from yellow (chromate, CrO4²⁻) to orange (dichromate, Cr2O7²⁻) as the equilibrium shifts. |
Added NaOH to shift the equilibrium back toward chromate ions. - |
Orange to Yellow |
Reaction 2 HCl (colorless) AgNO3 (colorless) CoCl2 (Pink (when hydrated) or blue (when dehydrated)) |
CoCl2 in the presence of Cl⁻ ions: Formed a blue complex, CoCl42- |
The addition of water dissolved the AgCl precipitate (to some extent) and hydrated CoCl42-, turning the solution back to pink (Co(H2O)62+). |
Blue (from CoCl42-) to Pink (from Co(H2O)6). |
Reaction 3 NH4Cl saturated (colorless) HCl (colorless) NH4Cl solid (white crystalline solid) |
The solution remained colorless, with the possible formation of more solid NH4Cl |
Dilution with water can redissolve the precipitated NH4Cl by reducing the concentration of chloride ions. |
No visible color change, but the solid NH₄Cl would dissolve. |
Reaction 4 NaOH (colorless) HCl (colorless) Methyl Orange (Orange in neutral solutions)
|
Mixing NaOH with HCl while using methyl orange has led to a transition from yellow to red as the pH becomes acidic |
Added NaOH to a solution that was red due to methyl orange in acidic conditions will shift it back toward yellow as the pH becomes more basic. |
Red to Yellow. |
Reaction 1 for shifting: 0.1 M K2CrO4 (potassium chromate), 1 M NaOH, and 3 M HCl
Adding NaOH: NaOH provides OH⁻ ions, which react with the H⁺ ions:
OH−+H+ → H2O
This decreases the concentration of H⁺ ions, causing a shift to the left to produce more H⁺ ions and increase the concentration of CrO₄²⁻. The formation of chromate ions leads to a yellow color.
Adding HCl: HCl dissociates into H⁺ and Cl⁻ ions. The increase in H⁺ ions shifts the equilibrium to the right to reduce the H⁺ concentration, forming more Cr₂O₇²⁻ ions, which causes a color change to orange due to the formation of dichromate ion
to generate a solution
a solution
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