Data Table 1. Anion Confirmation Tests. Chemical Anion Addition of AgNO 3 Additi
ID: 879370 • Letter: D
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Data Table 1. Anion Confirmation Tests.
Chemical
Anion
Addition of AgNO3
Addition of HCl
NaBr
Bromide
It became white and cloudy
Still was white and cloudy
Na2CO3
Carbonate
Clear inside white and cloudy around the outside
Still white and cloudy but bubbles start to form
NaCl
Chloride
Turn white cloudy on bottom clear on top
Still white cloudy on bottom clear on top
NaI
Iodide
In the middle very dark and cloudy fades out lighter white around the middle
Became a little separate
Na2SO4
Sulfate
Clear
Became white and cloudy
Na2S
Sulfide
Turn a brown color in the middle but separated from the clear
The brown becomes more separate from the clear
Unknown #103
CO3^2-
White and cloudy
Small particles
Bubbles form white and cloudy
Unknown #104
S^2-
Turn brown color I the middle around clear
Some of the brown disappeared and become separate
Data Table 2. Cation Flame Tests.
Chemical
Cation
Flame Observations
KI
Potassium
LIGHT PINK
CaCl2
Calcium
RED
LiOH
Lithium
FUSHA PINK
NaCl
Sodium
ORANGE
Cu(NO3)2
Copper
TEAL
Unknown #105
Copper
TEAL
Unknown #106
Potassium
LIGHT PINK
Unknown #107
Calcium
RED
Data Table 3. Complete Chemical Identification.
Chemical
Cation
Anion Test Observations
Anion
Complete Chemical Name and Formula
Unknown #105
Copper
with AgNO3: No chane
No3^2-
Copper(II) nitrate, Cu(NO3)2
Unknown #106
Potassium
with AgNO3: In the middle very dark and cloudy fades out lighter white the middle
I-
Potassium iodide, KI
Unknown #107
Calcium
With AgNO3: Turn white cloudy on the bottom on top
Cl-
Calcium chloride, CaCl2
1. Use your results and observations in Data Tables 1, 2, and 3, to create a flow chart for the identification of an unknown (both an unknown anion and cation), using the AgNO3 and HCl confirmation tests and the cation flame tests.
Chemical
Anion
Addition of AgNO3
Addition of HCl
NaBr
Bromide
It became white and cloudy
Still was white and cloudy
Na2CO3
Carbonate
Clear inside white and cloudy around the outside
Still white and cloudy but bubbles start to form
NaCl
Chloride
Turn white cloudy on bottom clear on top
Still white cloudy on bottom clear on top
NaI
Iodide
In the middle very dark and cloudy fades out lighter white around the middle
Became a little separate
Na2SO4
Sulfate
Clear
Became white and cloudy
Na2S
Sulfide
Turn a brown color in the middle but separated from the clear
The brown becomes more separate from the clear
Unknown #103
CO3^2-
White and cloudy
Small particles
Bubbles form white and cloudy
Unknown #104
S^2-
Turn brown color I the middle around clear
Some of the brown disappeared and become separate
Explanation / Answer
unknown number 5
Add NH3 dropwise to the solution, stir or shake the solution, and observe any reaction.
A ppt of metal hydroxide will be formed.
Continue adding ammonia. Copper hydroxides fom a complex ion and redissolve. The colour of complex ion will be blue.
Cu+2 + OH- --> Cu(OH)2 ppt
Cu+2 + NH3 ( excess) ---> Cu(NH3)4 ( blue colour)
Nitrate ion:
The aluminium powder is a powerful reducing agent and converts the nitrate ion, NO3–, into ammonia gas, NH3 Boil the suspected nitrate with sodium hydroxide solution and fine aluminium powder (Devarda's Alloy) or aluminium foil.the fumes contain ammonia, which turns red litmus blue.
Confirmatorytest: Add iron(ii) sulphate solution and then conc. sulphuric acid (the 'brown ring' test), a brown ring is formed where the liquid meets due to formation of NO complex of iron(II).
Unknown 6:
Potassium: A little of the metal salt or other compound is mixed with a few drops of concentrated hydrochloric acid and a sample of the mixture is heated strongly in a bunsen flame on the end of a cleaned nichrome wire : violet–lilac flame will be observed
Chloride ion : add dilute nitric acid and silver nitrate solution, white ppt of AgCl will be formed.
Unknown 7:
Calcium ion: A little of the metal salt or other compound is mixed with a few drops of concentrated hydrochloric acid and a sample of the mixture is heated strongly in a bunsen flame on the end of a cleaned nichrome wire, brick–red (yellowish red) flame observed
Iodide ion: add dilute nitric acid and silver nitrate solution, yellow ppt of AgI will be formed.
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