
Take our free diagnostic organic chem exam! Click below.
Free DAT Organic Chemistry Exam
An aqueous solution of a metal nitrate (“X”NO3) forms a precipitate when magnesium sulfate (MgSO4) is added. However, a separate sample of the metal nitrate does not form any precipitate when mixed with hydrogen perchlorate (HClO4). What could this metal “X” be?

Loading ...
Correct Answer: C. Lead (Pb).
The correct answer is C. First of all, we can immediately disregard answers A, B, and E. Nearly all compounds containing sodium, potassium, or zinc are soluble. Thus, we are left with answers C and D. Of the two, we realize that sulfur does not bind with sulfate. Sulfur sulfate does not exist. Lastly, you could eliminate sulfur by recognizing that it’s a nonmetal, not a metal. We recognize as well that lead compounds are rarely soluble, but lead perchlorate is. Thus, answer C is the correct answer.
Subscribe below to receive the DAT Question of the Day delivered straight to your inbox every morning.