Respuesta :

Answer:

See below

Explanation:

From periodic chart

Mg = 24.305 gm per mole

24.305 * 3 = 72.915 gm

Na = 22.989

Cl = 35.45            summed = 58.439 gm per mole

   58.439 * 4.2 = 245.4438 gm