The FDA recommends that adults ingest less than 2.4 g of sodium per day. How many liters of softened water, containing a sodium concentration of 0.050% sodium by mass, have to be consumed to exceed the FDA recommendation? (Assume a density of 1.0 g>mL for water.)

Answer 1

0.050% means 0.050 g Na/100 g H20 = 0.050g Na/100 mL = 0.50 g Na/L.
0.50g Na/L x ?mL = 2.4g