VOL.3, No. 9
A QUALITATIVE ANALYSISFUZZLE
1071
A QUALITATIVE ANALYSIS PUZZLE CARLOTTO, UNIVERSITYOR MAINE,ORONO, MAINE
The puzzle given here is somewhat different from all standard types of puzzles. A good knowledge of the properties of the ions is required to solve it if no references to text-books are made. The idea is to identify ten unknown solutions by studying their reactions with each other. Thus a certain group of ten solutions of single simple inorganic compounds (A, B, C, -, -, -, -, -, -, J) was taken and mixed together in all possible combinations of pairs. The observations, as given in the following table a t the junction of lines drawn from the letters representing the said solutions in the top and left margins, were noted. Thus, solution A added to solution B gave a yellow precipitate, soluble in HNOJ; solution A added to solution C gave a white precipitate, soluble in HNOI, etc. Following the table are a few other observations which were nnted. The problem is to identify the ten solutions from the data given. A Yellow PPf. sol.
in HNOI White ppt 101. in HNOa
Red ppt. sol. in acids and NHaOH
White ppt. 301. in HNOI
mite p p t sol. in acids
mite ppt. sol. in NHlOH
vellow ppt. sol.
Yellow ppt. sol. in HCI and HNOI
White White ppt. in- ppt. red sol. in solution acids ppt. sol. sol. in in acids NHdOH
kmonyellow PPt. sol. in acids
yellow ppt. in-I. in acids sol. in
in HNOI
Yellow ppt. 301. in HNOI
Na,s,Oa White p p t sol. in HNOI
White ppt. sol. in acids
mite NO ppr ppt. Soh. gives purple color with CCI,
Red ppt. Brown
801.in ppt. sol. acids sol. in HCI in NHaOH
Black ppt. sol. in HNOI
No ppt. If HCI is added white PPt.
Rlaek
Dark
ppt. in- green sol. in ppt. sol. acids ex- in acids cept C0"C
HPO* or HNOa
white mite p p t 501. ppt. sol. in acid. in HNOI and a1kalis
No ppt.
White ppt. sol. in acids gar evol, turns PbAn black
Yellow
ppt. $01. in nlkali sulfidep
A
I
B
White p p t sol. in HNOS
White ppt. sol. in acids
White ppt. inrol. in acids except
No ppt. orange solution
C white ppt. sol, in N&OH
D E F G Redwhite white No ppt. brown ppt. sol. ppt. sol. slight ppt. sol. in acids in acids cfferves. in acids with cene evol. of
Slight ppt. sol. in N-OH Glans etched by fumes
2 gases white evolved ppt. on htg. insol. limewater in acids milky except combus- eonc. tible HBOa
R
I
No ppt.
co, J ,
cone.
H&OI
ADDITZONAL
No ppt.
No reaction
DATA
All solutions are colodes eexcept solutionn B and D which are light yellow. Solutions G. H. and J are aeido. Solution A gives the b r o w ring test. Soltltion E gives a green flame test and solution I a yellow flame test.
(Answers to be published i n the next issue.)
White Evol. of pP. CO, Colloidal Odor SO.
