First we start off by making the first part of the equation: Copper Nitrate plus Sodium: Cu(SO3)2 + Na
This reaction is a single replacement one. Na (Sodium) is a metal so it has a positive charge which means it is going to react with the part of Copper Nitrate that has a Negative charge. It's going to react with the nitrate ion because copper is positive and it can't react with it.
Since nitrate is reacting with sodium :
Nitrates charge is +1
Sodiums charge is +1
You get NaSo3 +Cu
Now you have both the reactants and the product. all you have to do is balance them:
Cu(SO3)2 + Na--> NaSO3 + Cu
First you would see if copper is balanced (it is)
Then you see Nitrate is balance (its not)
On the reactant side you have 2 nitrate
and on the product side you have 1 so you have to put a coefficient 2 in front of NaSO3
Cu(SO3)2 + Na --> 2NaSO3 + Cu
Now sodium isnt balanced because there is 2 on the product so you would put a 2 as a coefficient on the reactant side:
Cu(SO3)2 + 2Na --> 2NaSO3 + Cu
AND NOW ITS BALANCED
We'll write the skeletal equation first and we'll identify the reactants and the products of reaction.
Cu(NO3)2 + Na --> NaNO3 + Cu
The reactants are copper nitrate and sodium and the products of reaction are sodium nitrate and copper.
Now, we'll inspect how many atoms or ions are to the left side and how many atoms or ions are to the right side.
We notice that there is one less nitrate ion produced, therefore, we need to put the coefficient 2 in from of NaNO3. This coefficient balances the number of NO3 on both sides but imbalances the number of Na atoms. There are 2 atoms of Na on the right side, while there is one atom of Na to the left side. We'll put 2 in front of Na, on the reactants side.
The final balanced equation is:
Cu(NO3)2 + 2Na --> 2NaNO3 + Cu