Answer
First column (Soluble): $LiOH, K_3PO_4, Pb(NO_3)_2, Na_2CO_3, Ca(C_2H_3O_2)_2, CaCl_2$ and $CuI_2$.
Second column (Insoluble): $CoCO_3, SrSO_4, PbI_2, PbBr_2, Hg_2Br_2, AgCl$ and $Cu(OH)_2$.
Work Step by Step
1. Classify each compound as soluble or insoluble:
$LiOH$, $K_3PO_4$, $Pb(NO_3)_2$, $Na_2CO_3$ and $Ca(C_2H_3O_2)_2$:
Any $K^+$, $NO_3^-$, $Na^+$, $Li^+$ or $C_2H_3O_2^-$ compound is soluble.
$CoCO_3$:
Most $CO_3^{2-}$ compounds are insoluble.
$SrSO_4$:
$SO_4^{2-}$ compounds with $Sr^{2+}$ are insoluble.
$PbI_2$, $PbBr_2$ and $Hg_2Br_2$ and $AgCl$:
$Hg^{2+}$, $Pb^{2+}$ and $Ag^+$ compounds with $Cl^-$, $I^-$ or $Br^-$ are insoluble.
$Cu(OH)_2$:
Most $OH^{-}$ compounds are insoluble.
$CaCl_2$ and $CuI_2$:
Most $Cl^-$ and $I^-$ compounds are soluble.
2. Now, create a column with all the soluble compounds, and another one with the insoluble ones.
First column: $LiOH, K_3PO_4, Pb(NO_3)_2, Na_2CO_3, Ca(C_2H_3O_2)_2, CaCl_2$ and $CuI_2$.
Second column: $CoCO_3, SrSO_4, PbI_2, PbBr_2, Hg_2Br_2, AgCl$ and $Cu(OH)_2$.
