It's important to know that since there is excess sodium, Cl2 is the limiting reagent and we always use the mol of the limiting reagent to find the moles of the product.
You can then find moles of NaCl by looking at the chemical equation (You can read the equation like 1 mol of Na reacts with 1 mol of Cl2 to form 2 mol of NaCl).
So now, since we have 2 mol of Cl2, the mole of NaCl will be 2*2=4 mol. You can then find the molar mass of NaCl (this is done just by looking at the periodic table, adding, etc.) and multiply this number by 4 to get the mass of NaCl.
Hope this helps. I notice you have some similar questions posted. I think if you understand this one, you can figure out the rest.