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The following passage is a narrative description of experimental results for an

ID: 499389 • Letter: T

Question

The following passage is a narrative description of experimental results for an unknown metal solution. Use your data for lab 10 to evaluate these results and identify the unknown metal. Write a brief conclusion (-100 words) stating your conclusion and outlining the reasoning/justification for your conclusion. You may write this justification below or attach a typed page. A portion of the unknown metal was digested using hot, concentrated nitric acid and dried to yield the metal nitrate salt. A 0.10M solution of this salt and tested using six 0.2M chemical spot test reagents: potassium chromate, sodium chloride, sodium hydroxide, sodium sulfide, ammonium hydroxide, and sodium phosphate. Reaction with chromate and hydroxide yielded orange precipitates. Reaction with sulfide and ammonium hydroxide yielded brown precipitates. Reaction with phosphate yielded a yellow precipitate. No visible reaction was observed with chloride.

Explanation / Answer

The metal is mercury and all of its salts, mercury chromate, mercury oxide (original hydroxide becomes oxide), mercury sulphide, mercury oxide (reaction with ammonium hydroxide) and mercury phosphate colors are matching with known colors of these compounds.