Question

lead salt solution+hcl= white precipitate of pbcl2 it is faster in room temperature

Answer 1

Lead nitrate reacts with HCl to form the insoluble lead chloride, which appears as the white precipitate.

Pb(NO3)2 + 2HCl = PbCl2 + 2HNO3.

The insoluble lead chloride reacts with excess Cl- ions (of HCl) to form a soluble complex, the tetrachloroplumbate(II) ion, PbCl4(2-).

PbCl2 + 2HCl = 2H(+) + PbCl4 (2-).

So, the white precipitate of PbCl2 redissolves in excess HCl.