Question

Which chemical equation represents a precipitation reaction? A. MgBr2 + 2HCl → MgCl2 + 2HBr B. K2CO3 + PbCl2 → 2KCl + PbCO3 C. 4LiC2H3O2 + TiBr4 → 4LiBr + Ti(C2H3O2)4 D. 2NH4NO3 + CuCl2 → 2NH4Cl + Cu(NO3)2

Answer 1

Answer:- The correct answer is B. $K_2CO_3(aq)+PbCl_2(aq)\rightarrow 2KCl(aq)+PbCO_3(s)$

Explanations:- To predict which equation would form the precipitate, we use the solubility rules. As per the solubility rules, chlorides are soluble except the chlorides of $Ag^+$ , $Pb^2^+$ and $Hg_2^2^+$ .

Most of the carbonates are insoluble expect for group one metals and ammonium ion.

All acetates and nitrates are soluble.

Looking at the rules and all the reactions, it is second reaction that gives a precipitate of $PbCO_3$ . So, B is the right choice.

Answer 2

Answer:

B.   K2CO3 + PbCl2 → 2KCl + PbCO3