DAY 2:

Reactants(Color)

Observations Predicted Product

Net Ionic Equation Type of interionic reaction

Na2SO4

(clear)BaCl2

(clear)Precipitate formation

BaSO4

NaClBa2+ (aq) + SO4

2- (aq) BaSo4 (s)

Precipitate

Na2CO3

(clear)HCl

(clear)Gas formation H2CO3

NaCl2 H+ (aq) + CO3

2- (aq) H2CO3 (s)

Gas

NaCH3COO(clear)

HCl(clear)

Vinegar smell CH3COOHNaCl

H+ (aq) + CH3COO (aq) CH3COOH (aq)

Odor

NaCl(clear)

KNO3

(clear)No visible reaction

Na+ Cl- K+ NO3- no net ionic equation Ion formation

KMnO4

(violet)FeSO4

(orange)Red -> Iron precipitate

FeO4

K+ MnO4-

MnO4- (aq) + 8 H+ (aq) + 5

Fe2+ (aq) → Mn2+ (aq) + 4 H2O (l) + 5 Fe3+ (aq)

Redox

CuSO4

(blue)Little NH3

(clear)Less cloudy (blue) Cu(OH)2

2NH4+ SO4

2-Cu2+ (aq) + 2 OH- (aq)

Cu(OH)2 (s)Precipitate

CuSO4

(blue)Excess NH3

(clear)Cloudy (blue) [Cu(NH3)4]2+ Cu2+ (aq) + 4 HN3 (aq)

Cu(NH3)42+ (aq)

Complex

DAY 3:

Ba(NO3)2

(colorless)Na2SO4

(colorless)FeCl3

(orange)Pb(NO3)2

(colorless)KSCN

(colorless)K2Cr2O7

(orange)K2CrO4

(yellow-green)

Ba(NO3)2

(colorless)White ppt(Ba SO4)

Orange(NR)

Clear(NR)

Clear(NR)

Milky Yellow(BaCr2O7)

Milky Yellow

(BaCrO4)Na2SO4

(colorless)White ppt(Ba SO4)

Light Yellow(Fe(SO4)3)

Milky White

(PbSO4)

Clear(NR)

Clear Yellow Clear Yellow

FeCl3

(orange)Orange

(NR)Fe(SO4)3

(Light Yellow)

Glassy String

Black Dark Orange w/ppt

(Fe2(Cr2O7)3)

Dark Orange w/ppt

(Fe2(CrO4)3)Pb(NO3)2

(colorless)Clear(NR)

Milky White(PbSO4)

Glassy String

Clear(Pb(SCN)2)

Pastel Yellow w/ppt

(PbCr2O7)

Pastel Yellow w/ppt

(PbCrO4)KSCN

(colorless)Clear(NR)

Clear(NR)

Black Clear(Pb(SCN)2)

Light Orange

Clear Yellow

K2Cr2O7

(orange)Milky Yellow

(BaCr2O7)

Clear Yellow Dark Orange w/ppt

(Fe2(Cr2O7)3)

Pastel Yellow w/ppt

(PbCr2O7)

Light Orange

Light Orange

K2CrO4 Milky Clear Yellow Pastel Pastel Clear Light

(yellow-green)

Yellow(BaCrO4)

Yellow w/ppt

(PbCrO4)

Yellow w/ppt

(PbCrO4)

Yellow Orange

DAY 4-5:CATIO

NCOLOR NaOH

(little: 2 drops)

NaOH (excess: 3

drops)

NH3

(little: 2 drops)

NH3

(excess: 3 drops)

HCl H2SO4 KSCN (NH4)2S CH3CSNH2

Zn2+ Clear + +- + +- - - - + +Al3+ Clear + +- + ++ - - - + -Ba2+ Clear + ++ + ++ - + - - -Ni2+ Clear

Green+ ++ + +- - - - + -

Ag+ Clear + ++ + +- + - - + +Ca2+ Clear + ++ + ++ - - - - -Mg2+ Clear + ++ + ++ - - - - -Sr2+ Clear - - - - - + - - -Fe3+ Orange + ++ + ++ - - + + +

Mn2+ Clear Pink

+ ++ + ++ - - - + -

Na+ Clear - - - - - - - - -K+ Clear - - - - - - - - -

NH4+ Clear - - - - - - - - -

Cu2+ Clear Blue

+ ++ + +- - - - + +

DAY 6:

Cation ObservationZn2+ White Green (Bluish Green)Ba2+ Green (Pale/Apple Green)Ni2+

Ca2+ Yellow (Brick Red)Sr2+ Crimson Red (Crimson)Fe3+ Yellow (Gold)

Mn2+ Violet (Yellowish Green)Na+ Yellow (Intense Yellow)K+ Violet (Lilac)

NH4+ Green

Cu2+ Green (Blue-Green:Halide ; Green:Non-halide)

CationsWith color: Cu(blue), Ni(green), Fe(red/orange), Mn(brown)++: Ba, Ca, Mg, Sr+-: Zn, Ag, Al-: K, Na, NH4 => verify through flame test

DAY 10:

Solutions Color of Gas Odor of Gas Formula of Gas Test for Gas Observations

Na2CO3 + H2SO4 Colorless Vinegar-like CO2 Loss of precipitatesNa2SO3 + H2SO4 Colorless Mabaho H2SO3 Paper with K2Cr2O7 turns

from orange to light green

Na2S + H2SO4 Colorless Rubber-like H2S Faint orange to white Pb(CH3COO)2

Na2S2O3 + H2SO4 Colorless Gunpowder-like S2O3 Green-ishNaNO2 + H2SO4 Colorless Water-like NO2 Loss of precipitates

DAY 11:

Solution +BaCl2

( )+3M HCl + KMnO4

( )Na2SO4

( )-

Na2SO3

( )+ ++

Na2CO3

( )+ +- Purple

Na3PO4

( )+ +- Purple

Na2CrO4

( )+ (yellow) +- Red

NaF( )

+ (white) ++

Na2Cr2O7

( )+ (orange) +- Dark Red

NaNO2

( )- -

Na2S( )

+ ++

Na2S2O3

( )+ ++

Confirmatory Tests for Cations

Ag+: Add 5 drops 3M HCl to 10 drops unknown => Centrifuge and decant => Treat the ppt with separate 2mL portions of hot water (twice), shaking the test tube while the test tube is heated in the water bath. Decant the first 2mL portion of hot water and treat the precipitate with the second 2mL portion of hot water. => Centrifuge and decant => Add 1mL 6M NH3 to the precipitate and stir, => Add 6M HNO3 until acidic. White ppt confirms Ag+.

Fe3+, Ni2+: Add 5 drops 3M NaOH to 10 drops unknown => Centrifuge and decant. => Add the water to the precipitate and discard the washing. Add enough water to give a total volume of about 1 mL. Stir. => Divide the solution into two equal portions. => (1)Add 3 drops of 1M KSCN. A deep red color confirms the presence of Fe3+. => (2) Add 6M NH3 dropwise until the solution is basic to litmus. Add 5 drops of dimethyglyoxime [(CH3)2C2(NOH)2] solution and stir. Formation of a bright red precipitate confirms the presence of Ni2+.

Zn2+: (1)Add 5 drops 3M NaOH to 10 drops unknown. Centrifuge and decant. To the hydroxide of zinc, acid 6M NH3 drop by drop with stirring until it dissolves. Then add 2 drops of thioacetamide solution. Stir and heat in water bath for 3 minutes. Formation of a white precipitate, which dissolves, when the solution is acidified, confirms the presence of Zn2+. (2)To a fresh sample of unknown solution, add 10 drops of thioacetamide solution, stir and heat in the water bath for 3 minutes. Formation of white precipitate, which dissolves when the solution is acidified with 6M HCl, confirms the presence of Zn2+.

Cu2+: Add concentrated NH3 dropwise to the unknown solution until the solution is distinctly basic. A deep blue solution confirms the presence of Cu2+.

Ca2+: To the unknown solution, add 6 drops of H2O and concentrated CH3COOH dropwise. Then add 6 drops of 1M (NH4)2C2O4 and stir and heat in the water bath. The presence of a white precipitate confirms the presence of Ca2+.

Mg2+: To the unknown solution, add 6M NH3 until basic. Then add a small amount of dibasic ammonium phosphate (NH4)2HPO4 until Mg2+ precipitate as a white MgNH4HPO4 · 6H2O. If the precipitate dissolves in 6M CH3COOH, then the unknown contains Mg2+.

Al3+: Add 2 drops of aluminon reagent (C22H23O9N23) to the unknown solution. Add 3-5 drops of 6M NH3 o make the solution just basic. Mix this and let it stand. A flocculent precipitate colored a characteristic of red by the dye proves the presence of Al3+. If color and precipitate are indefinite, make the solution acid with 3M HCl, then basic with NH3, to build up the NH4

+ concentration so that the solution becomes less basic.

Confirmatory Tests for AnionsCO3

2-, SO32-, PO4

2-: Add 5 drops of BaCl2 to 10 drops unknown => Centrifuge and decant => Add 1mL of 3M acetic acid dropwise to the solid. Stir. Add 2 more drops of 3M CH3COOH. Stir, if bubbles are observed, continue to add 3M CH3COOH until no bubbles are noted. This destroys the CO3

2- Test for CO2 gas. => Divide the solution into 2 portions => (1) Add: 5 drops of 6M HCl, 5 drops of 0.5M Ba(CH3COO)2 or Ca(CH3COO)2, 5 drops of 3% H2O2. Formation of a white precipitate confirms presence of SO3

2-. => (2) Add: 5 drops of concentrated HNO3, 5 drops of ammonium molybdate solution. Heat in water bath for 1 minute. Formation of yellow precipitate confirms the presence of PO4

3-.

SO42-, CrO4

2-: Add 5 drops of BaCl2 to 10 drops unknown => Centrifuge and decant => Wash precipitate with 1mL water. Discard washings. Add 10 drops of 3M HCl and stir. If soluble proceed to (2). If not,

proceed to (1) => (1) Add BaSO4. Add 10 drops of H2O and 5 drops concentrated HCl and stir. White precipitate confirms SO4

2-. => (2) If soluble, BaCrO4. Add 6M NH3. Yellow precipitate confirms CrO42-.

Cl-, Br-, I-, CNS-: Add 5 drops AgNO3 to 10 drops unknown => Centrifuge and decant => AgCl (White/Dirty White), AgBr (Cream/Light Yellow), AgI (Yellow), AgCNS(White) => Add 2-6 drops 6M NH3. If soluble, add 3M HNO3. Stir until the solution is acidic (Check with litmus paper). Formation of white precipitate confirms the presence of Cl-. If insoluble proceed to next step => Divide precipitate into two. => (1) Place a very small amount of solid on a watch glass. Add 2 drops of 3M HCl and 1 drop of FeCl3. A red-blood solution confirms the presence of CNS-. => (2) Add 1mL of H2O to the bulk of the residue. Acidify with 6M CH3COOH. Add 1 microspatula of Zn dust and stir thoroughly for 3 mins. Centrifuge. => Disregard residue. Divide solution into two portions. => Test with litmus paper if solution is acidic. If not, acidify with a few drops of 6M CH3COOH. Add 10 drops of oil and a few crystals of NaNO2. Dilute with H2O to a volume of 2mL and shake vigorously. Did solution turn violet? If yes, I- is present. If no, proceed to next step. => Yellowish color in oil layer confirms the presence of Br-.

NO3-: (1) Place 1 drop of unknown in spot plate. Add 2 drops of concentrated H2SO4 and 1 drop of

napthylamine. Wait several minutes. Development of purple color confirms the presence of NO3-. (2)

Place 5-10 drops of unknown solution in a small teest tube. Without shaking the test tube, add 5 drops of freshly prepared solution of FeSO4 and 2-3 drops concentrated H2SO4. Observe the formation of brown ring at the junction of the solution. This indicates the presence of NO3

-. (3) Place a small crystal of FeSO4 in a depression of a spot plate. Add 1 drop of unknown and 1 drop of concentrated H2SO4. Formation of a brown ring around the crystal indicates the presence of NO3

-.

NO2-: (1) Add 1 micro spatula of urea to 1mL 3M HCl. Place 10 drops of this solution to 10 drops of

unknown. Evolution of gas confirms the presence of NO2-. (2) Add a freshly prepared solution of FeSO4 to

5 drops unknown. Then, add 2 drops of concentrated H2SO4. The rapid evolution of a brown gas confirms the presence of NO2

-.

CH3COO-: Warm 50mg of the unknown with 2 drops ethanol and 2 drops of sulfuric acid. The fruity odor of the product is apparent if the mixture is allowed to cool and then diluted with water on a watch glass.

CrO42-, Cr2O7

2-: acidify 10 drops unknown solution with concentrated sulfuric acid. Cool. Get 2 drops of this solution and mix to a solution of 1 drop 20% H2O2 and 5 drops ether. Shake. Blue color in the upper ethereal layer confirms the presence of CrO4

2- if the original solution is yellow, and Cr2O72—if the original

unknown solution is orange.

C2O42-, F-: acidify 10 drops of unknown solution with 3M CH3COOH. Boil. Add 10 drops of CaCl2 solution. If

precipitate forms, centrifuge. Wash the precipitate with hot water. Add 5 drops of 1M H2SO4 and heat. White residue confirms the presence of F-. Centrifuge and decant. Add 1 drop of dilute KMnO4 to the liquid. Decolorization of KMnO4 confirms the presence of C2O4

2-.

S2-, SO32-, PO4

3-: Add 5 drops of AgNO3 to 10 drops of unknown. => S2-(dark brown precipitate), SO32-(white

precipitate), PO43-(yellow precipitate).