Answer
a. There is no formation of solids.
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b. $2Ag^+(aq) + 2N{O_3}^-(aq) + 2K^+(aq) + S^{2-}(aq) \longrightarrow Ag_2S(s) + 2K^+(aq) + 2N{O_3}^-(aq)$
and
$2Ag^+(aq) + S^{2-}(aq) \longrightarrow Ag_2S(s) $
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c. $Ca^{2+}(aq) + 2 Cl^-(aq) + Na^+(aq) + S{O_4}^{2-}(aq) \longrightarrow CaSO_4(s) + 2Na^+(aq) + 2Cl^-(aq)$
and
$Ca^{2+}(aq) + S{O_4}^{2-}(aq) \longrightarrow CaSO_4(s)$
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d. $3 Cu^+(aq) + 6Cl^-(aq) + 6Li^+(aq) + 2 PO_4^{3-}(aq) \longrightarrow 6 Li^{+}+6Cl^-(aq) + Cu_3(PO_4)_2(s)$
and
$3 Cu^+(aq) + 2 PO_4^{3-}(aq) \longrightarrow Cu_3(PO_4)_2(s)$
Work Step by Step
1. Write the double replacement reactions, without specifying the physical states of the products.
a. $2KCl(aq) + Na_2S(aq) \longrightarrow K_2S + 2NaCl$
b. $2AgNO_3(aq) + K_2S(aq) \longrightarrow Ag_2S + 2KNO_3$
c. $CaCl_2(aq) + Na_2SO_4(aq) \longrightarrow CaSO_4 + 2 NaCl$
d. $3CuCl_2(aq) + 2Li_3PO_4(aq) \longrightarrow 6LiCl + Cu_3(PO_4)_2$
2. Predict if each product is soluble in water.
a. $K_2S$ contains the $K^+$ ion: Soluble.
$NaCl$ contains the $Na^+$ ion: Soluble.
b. $Ag_2S$ does not contain any ion of the list on Table 9.7: Insoluble.
$KNO_3$ contains the $K^+$ ion: Soluble.
c. $CaSO_4$ does not contain any ion of the list on Table 9.7: Insoluble.
$NaCl$ contains the $Na^+$ ion: Soluble.
d. $LiCl$ contains the $Li^+$ ion: Soluble.
$Cu_3(PO_4)_2$ does not contain any ion of the list on Table 9.7: Insoluble.
3. For those reactions with an insoluble product, write the ionic equation:
b. $2Ag^+(aq) + 2N{O_3}^-(aq) + 2K^+(aq) + S^{2-}(aq) \longrightarrow Ag_2S(s) + 2K^+(aq) + 2N{O_3}^-(aq)$
c. $Ca^{2+}(aq) + 2 Cl^-(aq) + Na^+(aq) + S{O_4}^{2-}(aq) \longrightarrow CaSO_4(s) + 2Na^+(aq) + 2Cl^-(aq)$
d. $3 Cu^+(aq) + 6Cl^-(aq) + 6Li^+(aq) + 2 PO_4^{3-}(aq) \longrightarrow 6 Li^{+}+6Cl^-(aq) + Cu_3(PO_4)_2(s)$
4. Remove the repeated ions to get the net ionic equation.
b. $2Ag^+(aq) + S^{2-}(aq) \longrightarrow Ag_2S(s) $
c. $Ca^{2+}(aq) + S{O_4}^{2-}(aq) \longrightarrow CaSO_4(s)$
d. $3 Cu^+(aq) + 2 PO_4^{3-}(aq) \longrightarrow Cu_3(PO_4)_2(s)$
