An Introduction to Qualitative Analysis

An Introduction to Qualitative Analysis
Purpose:
Tests the ions of Mg2+, Ca2+, Sr2+, and Ba2+, and identify them separately. By using these observations, identify the unknown ion. Then tests the ions of SO42-, CO32-, Cl-, and I-,identify them separately, and use the observation to identify the unknown.

Procedure
Part I - Qualitative Analysis of Group 2 Elements

Mix 0.02M K2CrO4 with each Mg(NO3)2, Ca(NO3)2, Sr(NO3)2 and
Ba(NO3)2 together. Secondly, mix 0.1M (NH4)2C2O4 instead of 0.02M K2CrO4 together with the same reactants used before. Thirdly, mix 0.1M Na2SO4 with those reactants. Then, mix 0.1M NaOH with the same reactants used before again.
Some precipitates should forms ,record the observations in Table 1.
At last, identify those two unknown solution.

Part II- Qualitative Analysis of Selected Anions

First mix 1M HNO3 with each Na2CO3, Na2SO4, NaCl and NaI together.
Repeat these steps by placing 0.1M Ba(NO3)2 instead of 1M HNO3. Then mix 1M HNO3 for the reactants that formed precipitates. Repeat the first step by placing 0.1M AgNO3 instead of 1M HNO3. Then add 6M NH3 to those mixtures that contains precipitates in, and 1M HNO3 the mixtures contains precipitates . Using these observation, identify an unknown union. Recording all the observations in
Table 2.

Data and Observations:
Part I -Qualitative Analysis of Group 2 Elements
Table 1

REAGENTS
0.1M SOLUTIONS OF GROUP 2 CATIONS (AS NITRATES)

Mg2+
Ca2+

Sr2+

Ba2+

Unknown D
0.02M K2CrO4 no no
Light ppt
Light ppt(yellow)
No
0.1M (NH4)2C2O4 no Heavy ppt(white)
Heavy ppt(white)
Light ppt(white)
Heavy ppt(white)
0.1M Na2SO4 no no
Light ppt
Light ppt(white) no 0.1M NaOH
Light ppt
Light ppt no Light ppt(white)
Light ppt(white)
Part II- Qualitative Analysis of Selected Anions
Table 2
REAGENTS
0.1M SOLUTIONS OF GROUP 2 CATIONS (AS Na SALTS)

CO32-
SO42-
Cl-
I-
Unknown Z
1M HNO3
Bubble
No
No
No
No