Question 491999
Carry the units along to make sure they cancel nicely.
Oh no! There is no unit on the volume of ocean water!
It's probably L; if not you will have to add some more conversion factors.
x=NaCl mass in kg.
x kg = 4.1% * 1.71 g/mL * (1 kg/1000g) * (1000 mL / L) * 5.5 * 10^20 L
Cancel^4...
x kg = 0.041 * 1.71 * 5.5 * 10^20 kg.