Experiment 12A: Investigating Chemical Equilibrium Courtney.K
March.3rd, 2017
Block 4
Purpose: As on page 163 “Essential experiments for chemistry” experiment 12A: Investigating chemical equilibrium.
Materials: As on page 164 “Essential experiments for chemistry” experiment 12A: Investigating chemical equilibrium.
Procedure: As on page 164-166 “Essential experiments for chemistry” experiment 12A: Investigating chemical equilibrium. Omit step 4.
Observations:
Part 1: HBcg ←→ Bcg- + H+
Initial colour of bromcresol green in water: Blue | |||
Reagent added | Stress | Colour change and number of drops added | Direction of equilibrium |
HCl3 | H+ | Translucent Green, 1 | → |
More HCl3 | H+ | Translucent Yellow, 3 | → |
NaOH | OH- | Translucent Green, 2 | ← |
More NaOH | OH- | Translucent Blue, 3 | ← |
Part 2: Fe3+ (aq) + SCN-(aq) ←→ FeSCN 2+ (aq)
Reagent Added | Stress | Colour change and number of drops added | Direction of equilibrium |
KSCN | KSCN | Opaque Dark Red, 10 | → |
FeCl3 | FeCl | Translucent Red, 10 | → |
KCl | Spectator | Transparent Orange, 10 | - |
NaOH | OH- | Translucent yellow, 10 | ← |
Part 3: Co(H2O)6 2+(aq) + 4Cl-(aq) ←→ CoCl4 2+ (aq) + 6H2O(l)
Colour of CoCl + HCl: Purple | Colour of CoCl2 + H2O: Pink | ||
Stress | Colour Observation | Direction of Equilibrium | |
Step 4 | HCl | Translucent Pink | ← |
Step 5 | Cl- | Translucent Blue | → |
Step 6 | Cl- | Transparent Pink | ← |
Part 5:
0.1M CuSO4 | +3 Drops NH3 | + more NH3 | 1M HCl added | |
Appearance | Transparent | Same colour but was translucent | Solution went opaque with particles present | Fizzed, then went back to transparent |