Experiment 9 PRE-LAB QUESTIONS 1. Below are some observations that were made when tests were carried out on solutions for specific ions. Based on the observed result, what is the most likely ion present in the solution? a. Heating produced a gas with a strong irritating odor; the gas changed moistened red litmus to blue. b. A white precipitate formed with barium chloride, BaCl c. A solution treated with potassium iodide, KI, turned reddish-brown and produced a violet colored layer with hexane. d. A solid produced a bright yellow color in a flame. e. A white precipitate formed with silver nitrate solution [AgNO,(a?).
Solution
The solution contains Na+, Cl-, NH4+, SO4-
a. Heating produces NH3 as a gas, which has strong irritating odor, and as ammonia is basic in nature it will change moistened red litmus to blue.
b. BaCl2 will form BaSO4 in presence of sulfate anion, and BaSO4 forms white precipitate.
c. KI reacts with sulfate to form SO2 (gas) and iodine (I2). Presence of SO2 make it reddish brown and violet colored layer with hexane is due to the formation of iodine, which dissolves in hexane to give violet color.
d. Sodium (Na+) ion produced a bright yellow color in a flame.
e. Silver nitrate forms white ppt. with Cl-, and forms AgCl. However, sulfate also forms white ppt. with Ag+ to form Ag2SO4 (dissolves in aq. acids, alcohols, acetone, ether, acetates, amides; Insoluble in ethanol etc.)
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Experiment 9 PRE-LAB QUESTIONS 1- Below are some observations that wer.docx
1. Experiment 9 PRE-LAB QUESTIONS 1. Below are some observations that were made when
tests were carried out on solutions for specific ions. Based on the observed result, what is the
most likely ion present in the solution? a. Heating produced a gas with a strong irritating odor;
the gas changed moistened red litmus to blue. b. A white precipitate formed with barium
chloride, BaCl c. A solution treated with potassium iodide, KI, turned reddish-brown and
produced a violet colored layer with hexane. d. A solid produced a bright yellow color in a
flame. e. A white precipitate formed with silver nitrate solution [AgNO,(a?).
Solution
The solution contains Na+, Cl-, NH4+, SO4-
a. Heating produces NH3 as a gas, which has strong irritating odor, and as ammonia is basic in
nature it will change moistened red litmus to blue.
b. BaCl2 will form BaSO4 in presence of sulfate anion, and BaSO4 forms white precipitate.
c. KI reacts with sulfate to form SO2 (gas) and iodine (I2). Presence of SO2 make it reddish
brown and violet colored layer with hexane is due to the formation of iodine, which dissolves in
hexane to give violet color.
d. Sodium (Na+) ion produced a bright yellow color in a flame.
e. Silver nitrate forms white ppt. with Cl-, and forms AgCl. However, sulfate also forms white
ppt. with Ag+ to form Ag2SO4 (dissolves in aq. acids, alcohols, acetone, ether, acetates, amides;
Insoluble in ethanol etc.)
