Discovering the Mystery of Eleven Test Tubes

Karen Radakovich Ph.D.
Mohammad Farhad
Brittany Cina
CH 223, Spring 08

Abstract: Eleven mystery test tubes labeled from K-1 to K-11 contained: 6M H2SO4, 6M NH3, 6M HCl, 6M NaOH, 1M NaCl, 1M Fe(NO3)3, 1M NiSO4, 1M AgNO3, 1M KSCN, 1M Ba(NO3)2, 1M Cu(NO3)2 respectively. The contents of the test tubes were determined by chemical experiments. Solution K-1 contained NiSO4 because when solution K-9, ammonia which was identified by its pungent odor, was added, an inky dark blue color was made. Iron (Fe (NO3)3) was determined to be in test tube K-2. KSCN was found in test tube K-11 since Fe (NO3)3 and KSCN makes a bloody color when mixed together. Flame tests were conducted in which K-8 …show more content…

In the lab, eleven test tubes containing unidentified solutions were obtained.
To indentify the unknown solutions, about two or three drops of the solution from one test tube was mixed in a depression of the spot plate with two or three drops of the solution from another test tube. The mixing of two solutions from two different test tubes was continued untill the tests were positive. Color changes, precipitate formation, smoke, heat, and odor of all the mixed solutions were observed and noted. In Table 1, ppt stands for that the two solutions precipitate when mixed with each other, Cc stands for changing color, and X stands for nothing occurs between the two solutions.

Table 1: Data of the eleven solutions | Cu(NO3)2 | Fe(NO3)3 | Ba(NO3)2 | H2SO4 | NaOH | HCl | AgNO3 | NiSO4 | NH3 | NaCl | KSCN | Cu(NO3)2 | X | | | | | | | | Cc | | | Fe(NO3)3 | | X | | | | | | | | | | Ba(NO3)2 | | | X | ppt | | | | | | | | H2SO4 | | | | X | | | | | | | | NaOH | | | | | X | | | | | | | HCl | | | | | | X | | | | | | AgNO3 | | | | ppt | ppt | ppt | X | | | | | NiSO4 | | | | | | | | X | | | | NH3 | | | ppt | | | | | | X | | | NaCl | | | | | | | | | | X | | KSCN | | Cc | | | | | | | | | X |

Results:
By following the solubility rules and other characteristics of the solutions and the mystery solutions were mixed together and