Question

Assertion: A solution of lead carbonate gives a dirty green precipitate with sodium hydroxide.
Reason: Lead ions can be identified by their characteristic color formation.
A.Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
B.Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
C.Assertion is correct but Reason is incorrect.
D.Assertion is incorrect but Reason is correct.
E.Both Assertion and Reason are incorrect.

Answer 1

This question gives the knowledge about the precipitation reactions. Precipitation reactions are the reactions which occur when two soluble salts containing solutions combine to form an insoluble salt. That insoluble salt is called precipitate.

Complete step-by-step answer: When lead carbonate $PbC{O_3}$ reacts with sodium hydroxide, it leads to the formation of a white precipitate of sodium trihydroxoplumbate $\left( {II} \right)$ and sodium carbonate.
The reaction is as follows:
$PbC{O_3} + 3NaOH + N \to Na\left[ {Pb{{\left( {OH} \right)}_3}} \right] \downarrow + N{a_2}C{O_3}$
In the above reaction sodium trihydroxoplumbate $\left( {II} \right)$ $Na\left[ {Pb{{\left( {OH} \right)}_3}} \right]$ is the precipitated out which is white in color.
This proves that lead carbonate is insoluble and soluble salts of lead produce white precipitate. And the lead ions are not identified by the characteristic color.

Additional information: Precipitation reactions are the reactions which occur when two soluble salts containing solutions combine to form an insoluble salt. That insoluble salt is called precipitate. Precipitate reactions are very helpful in determining the presence of different ions in the solution. A precipitate is generally insoluble in the solution. Precipitation reactions are generally double displacement reactions.
The components which get precipitated during the reactions are generally reactants which can be present in any state solid, liquid or gas.
The most common example of precipitation reaction is the reaction between silver nitrate and potassium chloride which leads to the formation of a solid precipitate of silver chloride. The reaction is as follows:
$AgN{O_3} + KCl \to AgCl + KN{O_3}$

Hence, option $E$ is correct.

Note: Double displacement reactions are the reactions in which two molecules displaces its ion with each other. Precipitation reactions are generally double displacement reactions. Precipitation reactions are the reactions which occur when two soluble salts containing solutions combine to form an insoluble salt.