There are 12 unknown solid samples in vials numbered A01 to A12 on your table. Each vial contains ab — Physical Chemistry — Kinetics Chemistry Question
Identification of Unknown Solid Samples
There are 12 unknown solid samples in vials numbered A01 to A12 on your table. Each vial contains about 100 mg of crystals or powder of one pure compound. The unknown samples are as following:
NaCl CdSO4 Pb(NO3)2 Ba(OH)2 Na2S2O3
BaCl2 FeSO4 KI NaHCO3 NH4SCN
Note:
(1) There are two duplicated unknown samples.
(2) The hydrated H2O of crystal is omitted in the formulas listed above.
On your table, there are also 14 empty droppers, 12 empty vials, 12 coffee stirrers, and 5 droppers containing the following reagents:
* AgNO3, aqueous solution (c = 0.1 mol dm–3),
3 % H2O2, aq.
* Na2S, aqueous sol. (c = 0.1 mol dm–3),
* HCl, aq. (c = 1 mol dm–3),
0.01 % phenolphthalein
Use the five reagents provided and mutual reactions between the unknown solutions to identify each unknown sample and write your answer (code number) in the blank of the Data Sheet 28.
Procedure:
1. Use the coffee stirrers provided to transfer about 20 mg of each unknown sample into separate empty vial, add about 1 cm3 of distilled water to each vial to make the unknown solutions and label them appropriately.
2. Use the five reagents provided and mutual reactions between the unknown solutions to identify each unknown sample.
Note:
(1) This practical exercise is a kind of spot test. You can do it on the provided pallet or on a sheet of white paper.
(2) Be sure to confirm your observations before writing your answers in the blanks of the Data Sheet.
Data Sheet 28:
Compound Code | Compound Code | Compound Code
KI _____ | BaCl2 _____ | Na2S2O3 _____
NaCl _____ | FeSO4 _____ | NH4SCN _____
Pb(NO3)2 _____ | CdSO4 _____ | NaHCO3 _____
Ba(OH)2 _____