Question

After the addition of H₂SO₄, the above sample is centrifuged and decanted. Which of the following cations remaining in the supernatant could you separate, by causing them to precipitate, with the addition of H₂CO₃? (Hint: H₂CO₃ is a source of HCO₃⁻ and carbonate ions. Select all that apply.)

Ag+	K+	NH4+
Hg22+	Pb2+	Mg2+
Sr2+	Ba2+	Cu2+
Al3+	Fe3+

(f) Choose one of the cations above and write the net precipitation reaction that occurs. (Use the lowest possible coefficients. Include states-of-matter under the given conditions in your answer.)

Answer 1

SOL:In above cations Pb²⁺ is to form precipitate,when carbonicacid is added.

Pb²⁺ +H₂CO₃ =PbCO₃+2H^{+
   (ppt)}