Question

Which of the following is a precipitation reaction? a) Zn (s) + 2 AgNO3 (aq) → 2 Ag (s) + Zn(NO 3) 2 (aq) b) 2 LiI (aq) + Hg 2(NO3)2 (aq) → Hg 2I2 (s) + 2 LiNO3 (aq) c) HCl (aq) + KOH (aq) → KCl (aq) + H 2O (l) d) NaCl (aq) + LiI (aq) → NaI (aq) + LiCl (aq) e) None of the above.

Answer 1

Answer: $2LiI(aq)+Hg_2(NO_3)_2(aq)\rightarrow Hg_2I_2(s)+2LiNO_3(aq)$

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

Precipitation is a type of displacement reaction in which one the products is formed in the solid state.

$2LiI(aq)+Hg_2(NO_3)_2(aq)\rightarrow Hg_2I_2(s)+2LiNO_3(aq)$