Please help me figure out and understand how to set up a effective procedure for

Question

Please help me figure out and understand how to set up a effective procedure for this experiment: In this experiment I need to identify eleven clear and colorless solutions using analytical techniques. The assignment gives a list of chemical compounds that are aqueous solutions. By using flame tests and pH tests and by mixing the solutions with one another I will have to match them up. Here are the list of solutions (they will be numbered 1 to 11 in the lab but their identities will not be known): 0.1M HCl 3% H2O2 0.1 M Na2C2O4 0.1M NH4Cl 0.1M Al(NO3)3 0.1M Ba(NO3)2 0.1M AgNO3 0.1M Na2CO3 0.1M Mn(NO3)2 0.1M Na2S2O3 0.1M ZnCl2 I have reviewed these chemicals but I am having trouble distinguishing which test to use and at what point in the lab. Some of the analytical tests that the pre-lab reading mentioned was the pH test. This can be used to identify any solutions that are acidic or basic. The pH of a neutral solution is 7 while acids have lower pH and bases have higher pH. We are told due to the imprecision of pH paper measurements you should only use this as a first test for strong acids and bases. [Among the solutions you will be using the strong acids all contain H+ and the strong bases contain CO3^-2]. We are told another analytical test is the flame test - "Many metal cations when exposed to the heat of a flame will emit brightly colored light. Of the cations you will be analyzing Ba^2+ produces a yellow flame and Na+ produces an orange flame. It may be difficult to distinguish the orange sodium flame from the ordinary flame color so do not use the flame test as the first test to find the Na+ solutions." The remaining tests involve mixing together two or more of the unknown solutions and observing any reaction. One common result will be the formation of a solid precipitate. An insoluble precipitate will form from certain pairs of cations and anions.

Explanation / Answer

Clear Colorless Solution

Analytical Technique with Observation

Explanation

0.1 M HCl

1. pH on litmus paper will be less than 1

2. Gives effervescence with Na2CO3

3. Gives precipitate with AgNO3

Effervescence is formed due to liberation of CO2 gas

3 % H2O2

1. Reacts with Na2S2O3 and oxidizes to sulphuric acid. pH litmus paper turns red.

2. Turns starch iodide paper blue.

Initial basic solution turns red on pH paper due to formation of sulphuric acid.

0.1 M Na2C2O4

(Sodium oxalate)

1. Forms a precipitate with Barium nitrate solution

Insoluble Barium oxalate precipitate is formed

0.1 M NH4Cl

1. Forms white gelatinous precipitate with Al(NO3)3

0.1 M Al(NO3)3

1. Forms white gelatinous precipitate with NH4Cl

0.1 M Ba(NO3)2

1. Forms a precipitate with Barium nitrate solution

2. Forms pale/apple green in flame test

Insoluble Barium oxalate precipitate is formed

Flame test: Characteristic emission spectrum of Barium ions.

0.1 M AgNO3

1. Gives precipitate with HCl

2. With Na2S2O3, forms white precipitate initially then turn to black precipitate

With HCl, insoluble silver chloride is formed.

0.1 M Na2CO3

1. pH on litmus paper will be between 10-12

2. Gives effervescence with HCl

0.1 M Mn(NO3)2

1. Forms precipitate with Na2CO3

2. Forms precipitate with Na2C2O4

Insoluble manganese carbonate precipitate is formed

Insoluble manganese oxalate precipitate is formed

0.1 M Na2S2O3

1. Reacts with HCl to form yellow precipitate

2. With silver nitrate, it forms a white precipitate which soon turns black

HCl reacts instantaneously with Na2S2O3 to form sulfur solid (yellow), sulfur di oxide gas and water

Silver nitrate forms white silver thiosulfate which degrades in water to black silver sulfide.

0.1 M ZnCl2

1. Forms precipitate when treated with Na2CO3

2. Forms white precipitate when treated with AgNO3 solution

Insoluble zinc carbonate is formed during the reaction

Insoluble AgCl is formed with AgNO3

Clear Colorless Solution

Analytical Technique with Observation

Explanation

0.1 M HCl

1. pH on litmus paper will be less than 1

2. Gives effervescence with Na2CO3

3. Gives precipitate with AgNO3

Effervescence is formed due to liberation of CO2 gas

3 % H2O2

1. Reacts with Na2S2O3 and oxidizes to sulphuric acid. pH litmus paper turns red.

2. Turns starch iodide paper blue.

Initial basic solution turns red on pH paper due to formation of sulphuric acid.

0.1 M Na2C2O4

(Sodium oxalate)

1. Forms a precipitate with Barium nitrate solution

Insoluble Barium oxalate precipitate is formed

0.1 M NH4Cl

1. Forms white gelatinous precipitate with Al(NO3)3

0.1 M Al(NO3)3

1. Forms white gelatinous precipitate with NH4Cl

0.1 M Ba(NO3)2

1. Forms a precipitate with Barium nitrate solution

2. Forms pale/apple green in flame test

Insoluble Barium oxalate precipitate is formed

Flame test: Characteristic emission spectrum of Barium ions.

0.1 M AgNO3

1. Gives precipitate with HCl

2. With Na2S2O3, forms white precipitate initially then turn to black precipitate

With HCl, insoluble silver chloride is formed.

0.1 M Na2CO3

1. pH on litmus paper will be between 10-12

2. Gives effervescence with HCl

0.1 M Mn(NO3)2

1. Forms precipitate with Na2CO3

2. Forms precipitate with Na2C2O4

Insoluble manganese carbonate precipitate is formed

Insoluble manganese oxalate precipitate is formed

0.1 M Na2S2O3

1. Reacts with HCl to form yellow precipitate

2. With silver nitrate, it forms a white precipitate which soon turns black

HCl reacts instantaneously with Na2S2O3 to form sulfur solid (yellow), sulfur di oxide gas and water

Silver nitrate forms white silver thiosulfate which degrades in water to black silver sulfide.

0.1 M ZnCl2

1. Forms precipitate when treated with Na2CO3

2. Forms white precipitate when treated with AgNO3 solution

Insoluble zinc carbonate is formed during the reaction

Insoluble AgCl is formed with AgNO3

Clear Colorless Solution

Analytical Technique with Observation

Explanation

0.1 M HCl

1. pH on litmus paper will be less than 1

2. Gives effervescence with Na2CO3

3. Gives precipitate with AgNO3

Effervescence is formed due to liberation of CO2 gas

3 % H2O2

1. Reacts with Na2S2O3 and oxidizes to sulphuric acid. pH litmus paper turns red.

2. Turns starch iodide paper blue.

Initial basic solution turns red on pH paper due to formation of sulphuric acid.

0.1 M Na2C2O4

(Sodium oxalate)

1. Forms a precipitate with Barium nitrate solution

Insoluble Barium oxalate precipitate is formed

0.1 M NH4Cl

1. Forms white gelatinous precipitate with Al(NO3)3

0.1 M Al(NO3)3

1. Forms white gelatinous precipitate with NH4Cl

0.1 M Ba(NO3)2

1. Forms a precipitate with Barium nitrate solution

2. Forms pale/apple green in flame test

Insoluble Barium oxalate precipitate is formed

Flame test: Characteristic emission spectrum of Barium ions.

0.1 M AgNO3

1. Gives precipitate with HCl

2. With Na2S2O3, forms white precipitate initially then turn to black precipitate

With HCl, insoluble silver chloride is formed.

0.1 M Na2CO3

1. pH on litmus paper will be between 10-12

2. Gives effervescence with HCl

0.1 M Mn(NO3)2

1. Forms precipitate with Na2CO3

2. Forms precipitate with Na2C2O4

Insoluble manganese carbonate precipitate is formed

Insoluble manganese oxalate precipitate is formed

0.1 M Na2S2O3

1. Reacts with HCl to form yellow precipitate

2. With silver nitrate, it forms a white precipitate which soon turns black

HCl reacts instantaneously with Na2S2O3 to form sulfur solid (yellow), sulfur di oxide gas and water

Silver nitrate forms white silver thiosulfate which degrades in water to black silver sulfide.

0.1 M ZnCl2

1. Forms precipitate when treated with Na2CO3

2. Forms white precipitate when treated with AgNO3 solution

Insoluble zinc carbonate is formed during the reaction

Insoluble AgCl is formed with AgNO3

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