Solutions of potassium carbon ate, copper(II) chloride, and lead(II) nitrate are

Question

Solutions of potassium carbon ate, copper(II) chloride, and lead(II) nitrate are each added to a beaker. Will any compound(s) precipitate from solution? Write a balanced net ionic equation for any precipitation reaction that occurs. List a series of tests that would determine the order of activity (least active to most active) for the following metals: Zn, Mn, and Ag. The laboratory instructor gives you a test tube containing Ag^+, Ba^2+ and Cu^2+ ions. Devise a reaction scheme that would allow you to selectively precipitate each of these ions. Write a balanced net ionic equation for each precipitation reaction.

Explanation / Answer

1. Ksp of PbCO3 (7.4 x 10^-14) is lower than the Ksp of CoCO3 (1 x 10^-10), therefore, PbCO3 would precipitate out first from the solution,

2. Reaction of each with HCl

Ag would not react with HCl to form H2 gas, that is Ag+ cannot displace H+ from its solution. It forms AgCl precipitate instead.

Mn also does not react to form H2 gas

Zn on the other hand would react to form H2 gas in solution

So, Zn is most reactive of the three.

When reacted with Br2,

Ag would react to form Br- and Ag+.

Whereas, Mn would not react in this manner.

Thus Ag is more reactive than Mn

Therefore reactivity order in increasing order = Mn < Ag < Zn

3. Ag+, Ba2+ and Cu2+

Add dil HCl to the mixture, AgCl precipitates out of solution

Ag+ + Cl- ---> AgCl (ppt)

filter.

To the acidic mixture of Ba2+ and Cu2+, pass H2S gas,

black precipitate of CuS is formed, filter

Cu2+ + S^2- --> CuS(ppt)

the remaining is Ba2+ which can be precipitated by adding anouhg NH4OH and NH4Cl with (NH4)2CO3 to form BaCO3 precipitate.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.