Chemical Equilibrium
Labs p208
Thymol Blue Equilibrium
Thymol Blue (Yellow Form)Thymol Blue (Yellow Form) Thymol Blue + H+ (Blue)
Thymol Blue Equilibrium Stresses and Results
Thymol Blue (Yellow Form)Thymol Blue (Yellow Form) Thymol Blue + H+ (Blue)
1. Stress: Add HCl (H+). Result: Green ColourGreen Colour
2. Stress: Add more HCl. Results: Yellow ColourYellow Colour
3. Stress: Add NaOH (OH-) reacts with H+ to form H2O)
Result: Green ColourGreen Colour
4. Stress: Add more NaOH. Results: Blue ColourBlue Colour
Equilibrium Involving Thiocyanatoiron III Ion
Fe(H2O)63+ (AmberAmber) + SCN1- Fe(SCN)(H2O)5
2+ (D. Red)
Equilibrium Involving Thiocyanatoiron III Ion
Fe(H2O)63+ (AmberAmber) + SCN1- Fe(SCN)(H2O)5
2+ (D. Red)
a) Add KCl (Fe3+ forms an insoluble ppt [FeCl3] with Cl1-)
Result: Amber Colour Amber Colour
b) Add Fe(NO3)3 Possible Stresses: Fe+3 and NO3 –
Result: Darker RedDarker Red
c) Add KSCN Possible Stresses: K+ and SCN-
Result: Darker RedDarker Red
d) Add NaOH (Fe3+ forms ins. ppt [Fe(OH)3] with OH1-)
Result: First OrangeFirst Orange and then Amber ColourAmber Colour
Equilibrium Involving Cobalt II Complexes
Co(HCo(H22O)O)662+2+ (aq) + 2 Cl1- (aq) Co(HCo(H22O)O)44ClCl22 (aq) + H2O (ℓ)
a) Add HCl. Result: Purple Colour Purple Colour
b) Add H2O. Result: Pink ColourPink Colour
c) Add Heat. Result: Purple Colour Purple Colour
d) Remove Heat (Cool). Result: Pink ColourPink Colour
Equilibrium Involving Chromate and Dichromate Ions
CrCr22OO772-2- (aq) + 2 OH1- (aq) 2 CrO2 CrO44
2-2- (aq) + H2O (ℓ)
(Orange)(Orange) (Yellow)(Yellow)
Equilibrium Involving Chromate and Dichromate Ions
CrCr22OO772-2- (aq) + 2 OH1- (aq) 2 CrO2 CrO44
2-2- (aq) + H2O (ℓ)
(Orange)(Orange) (Yellow)(Yellow)
a)a) Add NaOH. Result: Add NaOH. Result: OrangeOrange turns turns YellowYellow (yellow stays yellow) (yellow stays yellow)
b)b) Add HCl. Result: Add HCl. Result: Yellow Yellow turns turns Orange Orange (orange stays orange) (orange stays orange)
c)c) Add KAdd K22CrOCrO4 4 Result: Colour in both is Result: Colour in both is OrangeOrange
d)d) Add KAdd K22CrCr22OO7 7 Result: Colour in both is Result: Colour in both is YellowYellow
e)e) Add Ba(NOAdd Ba(NO33))2 2 (BaCrO(BaCrO44 is insoluble while BaCr is insoluble while BaCr22OO77 is soluble) is soluble)
Result: Chr. sol. Result: Chr. sol. YellowYellow, Dichr. Sol. , Dichr. Sol. OrangeOrange
Ba(NOBa(NO33))2 2 in beakerin beaker
KK22CrOCrO44 in graduate in graduate
Equilibrium With Copper II Complexes
Cu(HCu(H22O)O)442+2+ (aq) + 4 NH4
+ + 4 OH- Cu(NH3)42+ (aq) + 4 H2O
(Light Blue)(Light Blue) (Deep Blue)
Equilibrium With Copper II Complexes
Cu(HCu(H22O)O)442+2+ (aq) + 4 NH4
+ + 4 OH- Cu(NH3)42+ (aq) + 4 H2O
(Light Blue)(Light Blue) (Deep Blue)
a) Add NH3 (aq) (NH3 (aq) is NH4+ + OH-)
Result: The light blue colour turns a deeper blue
b) Add more NH+. Result: The colour Yet Deeper BlueYet Deeper Blue
c) Add HCl (Yields H+ and Cl-). The deep Bluedeep Blue Light BlueLight Blue
End of Lab Results
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