Question

Separate samples of a solution of an unknown ionic compound were treated with dilute solutions of Pb(NO3)2, AgNO3, and BaCl_2. Precipitates formed in all three cases. Which of the following could be an anion of the unknown salts? (Select all that apply.)

a. Nitrate (NO3^-)
b. Silver (Ag+)
c. Chloride (Cl^-)
d. Barium (Ba2+)

Answer 1

The potential anions of the unknown salts could be chloride (Cl-) and sulfate (SO4^2-).

Step-by-step explanation:

When solutions of soluble ionic compounds are mixed together, a precipitation reaction may occur if it results in the formation of an insoluble compound. In this case, separate samples of the unknown compound were treated with dilute solutions of Pb(NO3)2, AgNO3, and BaCl_2, and precipitates formed in all three cases. Based on the observations, we can determine the anions of the unknown salts.

To identify the anion, we need to consider the precipitates formed in each case. When AgNO3 is added, a white precipitate indicates the presence of chloride ions (Cl-). When Pb(NO3)2 is added, a yellow precipitate indicates the presence of chloride ions (Cl-) as well. Lastly, when BaCl2 is added, a white precipitate indicates the presence of sulfate ions (SO4^2-).

Therefore, the potential anions of the unknown salts are: chloride (Cl-) and sulfate (SO4^2-).