How do you prepare 0.2N Sodium chloride solution?

NaCl is the formula for Sodium Chloride, from that you can work out the gram formula mass.

RAM Na = 23

RAM Cl = 35.5

gfm (NaCl) = 58.5g mol-1

assuming that you need 0.1l of NaCl

m = 58.5*0.1

= 5.85g

So dissolve 5.85g in water for a 0.2 mole solution