Question

question 3 (2 points)
which of the following pairs of aqueous solutions will react when mixed?
nal + kcl
febr2 + nano3
(nh4)2co3 + kcl
lioh + cubr2

Explanation:

Step1: Recall double - displacement reaction rules

For two aqueous ionic compounds to react, they must form a precipitate, a gas, or water.

Step2: Analyze each option

• For $\ce{NaI + KCl}$, the possible products are $\ce{NaCl}$ and $\ce{KI}$. Both are soluble in water, so no reaction.
• For $\ce{FeBr2 + NaNO3}$, the possible products are $\ce{Fe(NO3)2}$ and $\ce{NaBr}$. Both are soluble in water, so no reaction.
• For $\ce{(NH4)2CO3 + KCl}$, the possible products are $\ce{NH4Cl}$ and $\ce{K2CO3}$. Both are soluble in water, so no reaction.
• For $\ce{LiOH + CuBr2}$, the reaction is $\ce{2LiOH(aq)+CuBr2(aq)=Cu(OH)2(s) + 2LiBr(aq)}$. Copper(II) hydroxide $\ce{Cu(OH)2}$ is insoluble in water (a precipitate is formed), so a reaction occurs.

Answer:

LiOH + CuBr2