Question

A mixture of two salts is used to prepare a solution S , which gives the following results:

$\text{White precipitate(s) only} \underset{\text{Room temperature}}{\overset{\text{Dilute NaOH(aq)}}{\longleftarrow}} \text{S (aq solution of the salts)}\underset{\text{Room temperature}}{\overset{\text{Dilute HCl(aq)}}{\longrightarrow}} \text{White precipitate(s) only}$
The correct option(s) for the salt mixture is(are)

• A. Pb(NO3)2 and Zn(NO3)2
• B. Pb(NO3)2 and Bi(NO3)2
• C. AgNO3 and Bi(NO3)3
• D. Pb(NO3)2 and Hg(NO3)2

Answer 1

Answer: (A), (B), (C)

Pb(NO3)2 and Zn(NO3)2

Answer 2

The accurate choice is C.
Silver nitrate Ag(NO3​) and bismuth nitrate Bi(NO3​)3​) result in white precipitates.
Similarly, lead hydroxide Pb(OH)2​), zinc hydroxide Zn(OH)2​), and bismuth hydroxideBi(OH)3​) form white precipitates.
However, mercury hydroxide Hg(OH)2​) is unstable and does not yield a white precipitate.
Lead chloride PbCl2 is also noted as a white precipitate.

Therefore, options**(A)** , (B) , and (C) are deemed correct.