A 3.6-mL volume of seawater contains about 4.0 * 10-10 g of gold. The total volume of ocean water is about 1.5 * 1021 L. Calculate the total worth of all the gold in the world's oceans if the price of gold is $21.84 per gram.

total worth of all the gold: $3.64 E15 USD

Explanation:

density (δ) = mass/volume

∴ mass gold = 4.0 E-10 g

∴ volume = 3.6 mL = 3.6 E-3 L

⇒ δ = 4.0 E-10 g / 3.6 E-3 L

⇒ δ = 1.111 E-7 g/L

if volume = 1.5 E21 L:

⇒ mass gold = (δ) (v)

⇒ mass gold = (1.111 E-7 g/L) (1.5 E21 L)

⇒ mass gold = 1.666 E14 g

∴ price gold = $21.84 USD/g

for all the gold in the world's oceans:

⇒ price gold = (1.666 E14 g) ($21.84 USD/g)

⇒ price gold = $3.64 E15 USD