Approx. #36*g#? The key part of the answer is NOT the numerical figure but the dimensional analysis.

The product of the dimensions, #cancel(mol)xxg*cancel(mol^-1)=g#, which we require for a mass......and sometimes this sort of dimensional analysis allows you to check your answer, and determine whether you should divide or multiply.

And remember what a mole represents. It is simply a large number, #6.022xx10^23*mol^-1#.....

And here we have #6.022xx10^23*mol^-1xx0.61*molxx2# #"sodium"# and #"chloride"# ions..... Now this is dimensionally consistent as before. Is it? Why did I include the #2# factor in the product? Did I make a mistake?