Qualitative Analysis Of Cations: Ca2+, Ba2+, Mg2+, Zn2+ and Al3
TITLE: Qualitative Analysis Of Cations: Ca2+, Ba2+, Mg2+, Zn2+ and Al3+
OBJECTIVE:
• To identify the cations in known and unknown samples.
• To construct a logical flow chart for identifying the components of a mixture of unknown cations.
INTRODUCTION:
In this experiment we will study about qualitative analysis of cations: Ca2+, Ba2+, Mg2+, Zn2+ and Al3+. Qualitative analysis is an analytical procedure in which the question ‘what is present?’ is answered. In a systematic qualitative analysis scheme, each substance present is separated from the other substances. Then a confirmatory test is used to prove that the isolated substance is expected one. As the name indicates, qualitative analysis is not concerned with the quantity of substance present, but rather is simply used to confirm its existence. It is mainly focused on detecting ions in an aqueous solution. The solution is treated with reagents to test for reaction characteristics of certain ions, which may cause color change, solid forming and other obvious visible changes. The cations to be studied include some common alkaline earth metals, group 13 and Zn2+. These ions are not colored in solution, and most of their compounds are white. It is impossible therefore to use colors of solutions or precipitates to indicate which of these cations is present in solution. Instead, in this experiment, you will use differences in solubility to separate from each other.
APPARATUS:
Small test tubes, test tube rack, litmus paper, test-tube holders, hot plate, centrifuge, three beakers (250 mL or 400 mL), distilled water bottle, glass rod, dropping pipette, vial containing unknown solution.
CHEMICALS:
• Aqueous solutions of Ca2+, Ba2+, Mg2+, Zn2+ and Al3+
• 1 M Na2SO4 (aq)
• 6 M NaOH (aq)
• 6 M HCl (aq)
• 6 M NH3 (aq)
• 1 M HCl (aq)
• 0.25 M Ammonium oxalate, (NH4)2C204 (aq)
• 0.1 M NaH2PO4 (aq)
• 0.1 M Na2S (aq)
PROCEDURE:
Part A: Preliminary Observation
Doing the Experiment
OBJECTIVE:
• To identify the cations in known and unknown samples.
• To construct a logical flow chart for identifying the components of a mixture of unknown cations.
INTRODUCTION:
In this experiment we will study about qualitative analysis of cations: Ca2+, Ba2+, Mg2+, Zn2+ and Al3+. Qualitative analysis is an analytical procedure in which the question ‘what is present?’ is answered. In a systematic qualitative analysis scheme, each substance present is separated from the other substances. Then a confirmatory test is used to prove that the isolated substance is expected one. As the name indicates, qualitative analysis is not concerned with the quantity of substance present, but rather is simply used to confirm its existence. It is mainly focused on detecting ions in an aqueous solution. The solution is treated with reagents to test for reaction characteristics of certain ions, which may cause color change, solid forming and other obvious visible changes. The cations to be studied include some common alkaline earth metals, group 13 and Zn2+. These ions are not colored in solution, and most of their compounds are white. It is impossible therefore to use colors of solutions or precipitates to indicate which of these cations is present in solution. Instead, in this experiment, you will use differences in solubility to separate from each other.
APPARATUS:
Small test tubes, test tube rack, litmus paper, test-tube holders, hot plate, centrifuge, three beakers (250 mL or 400 mL), distilled water bottle, glass rod, dropping pipette, vial containing unknown solution.
CHEMICALS:
• Aqueous solutions of Ca2+, Ba2+, Mg2+, Zn2+ and Al3+
• 1 M Na2SO4 (aq)
• 6 M NaOH (aq)
• 6 M HCl (aq)
• 6 M NH3 (aq)
• 1 M HCl (aq)
• 0.25 M Ammonium oxalate, (NH4)2C204 (aq)
• 0.1 M NaH2PO4 (aq)
• 0.1 M Na2S (aq)
PROCEDURE:
Part A: Preliminary Observation
Doing the Experiment