Question

A substance dissolves in water to form a colorless solution. This solution reacts with aqueous silver nitrate in the presence of dilute nitric acid to give a yellow precipitate. What is the possible identity of the substance?

o A. Calcium iodide
o B. Copper (II) chloride
o C. Iron (II) iodide
o D. Sodium chloride

Answer 1

The substance that forms a yellow precipitate with aqueous silver nitrate is Calcium iodide, which indicates that the dissolved ion is iodide (I-).

Step-by-step explanation:

The question is about identifying a substance that forms a yellow precipitate when reacted with aqueous silver nitrate in the presence of dilute nitric acid.

Given the options, the correct answer is a substance that contains the iodide ion (I-), because the yellow precipitate indicates the presence of iodide ions.

In your exercise, this would mean that the correct choice is Calcium iodide (Option A). When calcium iodide reacts with silver nitrate, the following reaction occurs:

2 AgNO3(aq) + CaI2(aq) → 2 AgI(s) + Ca(NO3)2(aq)

where AgI is silver iodide, which is the yellow precipitate.