lab report qualitative analysis for identification of metal ions
OBJECTIVE
The main objective of this experiment is to carry out qualitative analysis to identify metal cations in unknown solution 1.
INTRODUCTION
An unknown material can be determined by using simple chemical tests and separations which is called as inorganic qualitative analysis. The separation of cations depends on the difference in their propensity to form precipitates. Separation scheme is used to classify cation into five groups on the basis of their physical and chemical behavior opposed to some reagents. Classification is based on whether there is formation of precipitates or not when metal cations react with the reagent. The five groups of cations and the characteristics of these groups are as follows:
i. Group I
Ag+, Hg+, Pb+
This group I cations form precipitate when reacted with HCl. ii. Group II
As3+, Bi3+, Cd3+, Cu2+, Hg2+, Pb2+, Sn4+
This group II cations form precipitate when reacted with H2S in acidic condition. iii. Group III
Co3+, Fe2+, Mn2+,Ni2+, Zn2+, *Al3+, Cr3+
This group III cations form precipitate when reacted with H2S in basic condition.
*Al3+ is separated as Al(OH)3 iv. Group IV
Ba2+, Ca2+, Mg2+, Sr2+
This group IV cations form precipitate when reacted with (NH4)2CO3.
v. Group V
Na+, K+
This group V cations form soluble salts when reacted with (NH4)2CO3.
The principle of periodicity applied to the results of this series of experiments. It helps, in trying to see the periodic pattern, to know the pattern that results when we do a separation and analysis of all metal ions.
PROCEDURE
Procedure A
1. 2 drops of 6 M HCl was added to 1 ml of the mixture of the metal cations.
2. The suspension was centrifuged for 1 minute as ppt. of chloride was formed.
3. 1 additional drop of 6 M HCl was added to the clear supernatant to check for complete precipitation.
4. The supernatant was centrifuged again for 1 minute as the ppt. was observed again.
5. The supernatant was decanted in a clean test tube.
6. The
The main objective of this experiment is to carry out qualitative analysis to identify metal cations in unknown solution 1.
INTRODUCTION
An unknown material can be determined by using simple chemical tests and separations which is called as inorganic qualitative analysis. The separation of cations depends on the difference in their propensity to form precipitates. Separation scheme is used to classify cation into five groups on the basis of their physical and chemical behavior opposed to some reagents. Classification is based on whether there is formation of precipitates or not when metal cations react with the reagent. The five groups of cations and the characteristics of these groups are as follows:
i. Group I
Ag+, Hg+, Pb+
This group I cations form precipitate when reacted with HCl. ii. Group II
As3+, Bi3+, Cd3+, Cu2+, Hg2+, Pb2+, Sn4+
This group II cations form precipitate when reacted with H2S in acidic condition. iii. Group III
Co3+, Fe2+, Mn2+,Ni2+, Zn2+, *Al3+, Cr3+
This group III cations form precipitate when reacted with H2S in basic condition.
*Al3+ is separated as Al(OH)3 iv. Group IV
Ba2+, Ca2+, Mg2+, Sr2+
This group IV cations form precipitate when reacted with (NH4)2CO3.
v. Group V
Na+, K+
This group V cations form soluble salts when reacted with (NH4)2CO3.
The principle of periodicity applied to the results of this series of experiments. It helps, in trying to see the periodic pattern, to know the pattern that results when we do a separation and analysis of all metal ions.
PROCEDURE
Procedure A
1. 2 drops of 6 M HCl was added to 1 ml of the mixture of the metal cations.
2. The suspension was centrifuged for 1 minute as ppt. of chloride was formed.
3. 1 additional drop of 6 M HCl was added to the clear supernatant to check for complete precipitation.
4. The supernatant was centrifuged again for 1 minute as the ppt. was observed again.
5. The supernatant was decanted in a clean test tube.
6. The
References: 1. Group IV Analysis. (n.d.). Retrieved from Cations Forming Insoluble Carbonates: http://isite.lps.org/mschmid3/web/documents/GroupIVanalysis.pdf 2. Inorganic Chemistry. (n.d.). Retrieved from Classification of the Cations and Anions: http://www.inc.bme.hu/en/subjects/inchem/sillabus/129-145.pdf 3. Leong, O. H. (2009). Qualitative Analysis. In Know Your 'O ' Level Chemistry (pp. 101-103). Singapore: Panpac Education Pte Ltd. 4. William L. Masterton, C. N. (2006). Quaitative Analysis. In Chemistry: Principles and Reactions, Updated Edition (pp. 436-437). Thomson Brooks/ Cole. 5. Wulfsberg, G. (2000). Application of HSAB: The Qualitative Analysis Scheme for Metal Ions. In Inorganic Chemistry (pp. 209-211). Sausalito: University Science Book.