Question

The mass of the ocean is about 1.8 X 10^21 kg. If the ocean contains 1.076% sodium ion, Na+, what is the mass in kilograms of sodium in the ocean?

Answer 1

Mass of sodium = Mass of ocean x percentage mass of sodium
= 1.8 x 10²¹ x 1.076 / 100
= 1.94 x 10¹⁹ kg