Lab 3 Qualitative Analysis Of Anion
LAB 3:
QUALITATIVE ANALYSIS
Part 2- ANIONS
Sameera Feroz Butt
Lab Partner: Ram Soni
Thursday January 30, 2014
Leilani Morales
CHEM1131-02
OBJECTIVE
The objective of this experiment was to use qualitative analysis to determine the chemical characteristics of four known anions by systemic confirmatory testing. The chemical characteristics observed were to be used to identify an unknown sample.
Sulphuric acid was to be added to a carbonate solution and an effervescent reaction would confirm the presence of carbonate anions. Another sample of carbonate solution was to be reacted with hydrochloric acid and the gaseous product was to be reacted with a suspended drop of barium carbonate. The presence of clouding in the droplet would also confirm the presence of carbonate anions.
Silver nitrate was to be added to chloride solution and the …show more content…
The addition of 6M acetic acid, HC2H3O2, acidified the solution, as confirmed by the litmus test. The newly acidic solution reacted with potassium nitrite, KNO2, reducing the nitrite to nitrogen dioxide as expressed by: I-(aq) + KNO2 → KI(aq) + NO2(g). The liberation of iodine in the reaction resulted in a brownish change in colouration of the solution (SUNY Chemisty, 2005). The failure of the sample to turn a reddish-brown may have been a source of error due to a failure to sufficiently rinse the cleaned test tube with DI water. Methylene chloride, CH2Cl2, which is a non-polar organic compound was added to the solution reacted with the iodide in the solution to form a violet coloured layer of denser solution, which settled at the bottom of the test tube. An alternative means of testing for the presence of iodide anions would have been to use starch, which forma a characteristic blue-black
QUALITATIVE ANALYSIS
Part 2- ANIONS
Sameera Feroz Butt
Lab Partner: Ram Soni
Thursday January 30, 2014
Leilani Morales
CHEM1131-02
OBJECTIVE
The objective of this experiment was to use qualitative analysis to determine the chemical characteristics of four known anions by systemic confirmatory testing. The chemical characteristics observed were to be used to identify an unknown sample.
Sulphuric acid was to be added to a carbonate solution and an effervescent reaction would confirm the presence of carbonate anions. Another sample of carbonate solution was to be reacted with hydrochloric acid and the gaseous product was to be reacted with a suspended drop of barium carbonate. The presence of clouding in the droplet would also confirm the presence of carbonate anions.
Silver nitrate was to be added to chloride solution and the …show more content…
The addition of 6M acetic acid, HC2H3O2, acidified the solution, as confirmed by the litmus test. The newly acidic solution reacted with potassium nitrite, KNO2, reducing the nitrite to nitrogen dioxide as expressed by: I-(aq) + KNO2 → KI(aq) + NO2(g). The liberation of iodine in the reaction resulted in a brownish change in colouration of the solution (SUNY Chemisty, 2005). The failure of the sample to turn a reddish-brown may have been a source of error due to a failure to sufficiently rinse the cleaned test tube with DI water. Methylene chloride, CH2Cl2, which is a non-polar organic compound was added to the solution reacted with the iodide in the solution to form a violet coloured layer of denser solution, which settled at the bottom of the test tube. An alternative means of testing for the presence of iodide anions would have been to use starch, which forma a characteristic blue-black