Question

Assertion :Lead is common element in 1${}^{st}$ and 2${}^{nd}$ group cations. Reason: A filtrate obtained after first group analysis of lead ion contains an appreciable concentration of this cation ( due to its solubility in $HCl$ solution), enough to give the test of the second group

• 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. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Lead is a common element in first and second group cations, this is because $PC{l}_2$ is for more soluble than the $chlorides$ of $Hg$ ang $Ag$, especially in hot water.

Therefore, $HCl$ in concentrations which completely precipitate $H{g}_2^{2+}$ and $A{g}^{+}$ may not be sufficient to do the same to $P{b}^{+2}.$ Also, higher concentrations of $C{l}^{-}$ can not be used. Thus, the filtrate obtained after the first group analysis of $P{b}^{+2}$ contains an appreciable concentration of this cation, enough to give the test of second group. Thus, $P{b}^{+2}$ is also included in second group.