Chemistry Lab Techniques Quiz

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What is the result of adding ammonia water to AgCl?

It turns black

It forms a white precipitate (correct)

It remains unchanged

It dissolves completely

How does the presence of metallic mercury manifest?

It remains colorless

It forms white precipitates

It turns gray upon acidification

It turns black in color (correct)

What signifies the presence of Hg2Cl2 in the reaction?

Yellow precipitate

No precipitate formed

Gray precipitate

White precipitate (correct)

Which color does mercurous ions precipitates appear in?

White Signup and view all the answers

Why do all samples show an absence of mercurous ion in the experimental results?

Insufficient complex formation with HgNH2Cl Signup and view all the answers

What is the color of the precipitate formed when lead (II) ion reacts with potassium chromate?

Yellow Signup and view all the answers

Which unknown samples showed yellow precipitations in the experimental results?

Unknown samples 2 and 3 Signup and view all the answers

What is the separating agent used to separate silver and mercurous ion in the analysis procedure?

Dilute ammonia Signup and view all the answers

What is the color of the precipitate formed when silver ion reacts with nitric acid?

White Signup and view all the answers

How is silver chloride separated from mercurous chloride based on their solubility?

Silver chloride is soluble in ammonia Signup and view all the answers

What does the efficiency of separation of silver ions from mercurous ions depend on?

Concentration of ammonia Signup and view all the answers

What is the main purpose of the group precipitation procedure in the given text?

Separating cations based on their solubility in water Signup and view all the answers

Why is it important to use colorless solutions instead of clear solutions in the given procedures?

To prevent confusion during identification tests for cations Signup and view all the answers

Which of the following cation groups becomes insoluble when they form chlorides according to the text?

Lead, silver, and mercury Signup and view all the answers

Why is it mentioned in the text that lead chloride may remain as a white residue after leaching with hot water?

Due to poor separation from mercurous chloride and silver chloride Signup and view all the answers

What characteristic of lead chloride makes its separation and identification challenging in the procedures described?

Partial separation from mercurous chloride and silver chloride Signup and view all the answers

Why does lead chloride have high solubility in water?

For easy dissolution when heated with hot water Signup and view all the answers

What is the purpose of the lab described in the text?

To identify ions in known and unknown mixtures of Group I cations Signup and view all the answers

How is the solubility product constant (Ksp) defined?

As the equilibrium between a solid and its respective ions in a solution Signup and view all the answers

How does the Ksp value relate to solubility?

Higher Ksp indicates higher solubility Signup and view all the answers

What does the comparison of lead chloride to silver chloride and mercurous chloride solubilities reveal?

Lead chloride is less soluble than silver chloride and mercurous chloride Signup and view all the answers

Why is examination as to color limited in determining the solution's identity?

Because certain colors may neutralize each other Signup and view all the answers

Why are good organizational skills and techniques considered essential in this lab?

To ensure correct results are obtained Signup and view all the answers

What is the purpose of keeping a 'waste' beaker near the work area?

To discard all solutions locally Signup and view all the answers

How can cross-contamination affect lab results?

It can cause false observations and incorrect conclusions Signup and view all the answers

What is the recommended method to clean glassware between uses?

Thoroughly rinse with deionized water Signup and view all the answers

How is the pH of a solution tested using litmus paper?

By contacting a stirring rod with litmus paper touched to the solution Signup and view all the answers

Which of these may indicate a positive test according to the text?

Formation of precipitate or residue Signup and view all the answers

What does 'centrifugate/supernatant' refer to in the context provided?

The liquid after mixture Signup and view all the answers