Complete and balance each of the following equations, some may have no reactions.

NaNO3(aq)+KCl(aq)-->

NaCl(aq)+Hg2(C2H3O2)2(aq)-->
note that Hg(I)^+1 interacts with another Hg(I)^+1 ion to produce the cation Hg2^2+

(NH4)2SO4(aq)+CuCl2(aq)-->

To balance chemical equations, we need to ensure that the number of atoms on each side of the equation is equal. Let's go through each of the given equations and balance them one by one.

1. NaNO3(aq) + KCl(aq) --> ?
We can start by balancing the sodium (Na) atoms. There is one Na atom on the left side, so we need one Na atom on the right side. Therefore, the balanced equation becomes:
NaNO3(aq) + KCl(aq) --> NaCl(aq) + ?

As for the nitrate (NO3) and chloride (Cl) ions, they are spectator ions since they stay unchanged during a reaction. Hence, the final balanced equation will be:
NaNO3(aq) + KCl(aq) --> NaCl(aq) + KNO3(aq)

2. NaCl(aq) + Hg2(C2H3O2)2(aq) --> ?
Since the question mentions that Hg(I)+1 interacts with another Hg(I)+1 ion to form the cation Hg2+2, we know that the mercury (Hg) atoms need balancing.
There are two Hg atoms on the left side, so we need two Hg atoms on the right side. Therefore, the balanced equation becomes:
NaCl(aq) + Hg2(C2H3O2)2(aq) --> Hg2Cl2(aq) + ?

As for the acetate (C2H3O2), sodium (Na), and chloride (Cl) ions, they are spectator ions. Hence, the final balanced equation will be:
NaCl(aq) + Hg2(C2H3O2)2(aq) --> Hg2Cl2(aq) + 2Na(C2H3O2)(aq)

3. (NH4)2SO4(aq) + CuCl2(aq) --> ?
To balance the atoms in this equation, we need to start with the sulfur (S) atoms. There is one S atom on the left side, so we need one S atom on the right side. Therefore, the balanced equation becomes:
(NH4)2SO4(aq) + CuCl2(aq) --> ? + H2SO4(aq)

Next, let's balance the nitrogen (N) atoms. There are two N atoms on the left side, so we need two N atoms on the right side. The balanced equation now becomes:
(NH4)2SO4(aq) + CuCl2(aq) --> ? + H2SO4(aq) + 2NH4Cl(aq)

Finally, the equation is balanced. However, if you need the specific product compound, you can check the solubility rules to determine if it forms a precipitate or remains aqueous.

Note: It's important to double-check the balanced equation using coefficients to ensure that the number of atoms is the same on both sides.