Question

A 1.0-mL volume of seawater contains about 4.0 x 10^-12 g of gold. The total volume of ocean water is 1.5 x 1021L .Calculate the total amount of gold (in grams) that is present in seawater and the worth of the gold in dollars. With so much gold out there, why hasn't someone become rich by mining gold from the ocean?

Answer 1

Answer is given below.

Step-by-step explanation:

`1mL=10^(-3)L`

So,
`1mL=10^(-3)L` seawater contains
`4.0* 10^(-12)g` of gold

hence
`1.5* 10^(21)L`seawater contains
`(4.0* 10^(-12)* 1.5* 10^(21))/(10^(-3))g` gold or
`6.0* 10^(12)g` gold

`1g gold=48.64\$`

So,
`6.0* 10^(12)g` gold =
`6.0* 10^(12)* 48.64\$ =2.9* 10^(14)\$`

Seawater contains majorly different kinds of salts e.g.
`CaCl_(2),MgCl_(2)` along with gold in very very small amount.

So, purification of seawater is more rigorous and more costlier than extracting gold from ores.

Hence investing money in mining gold from seawater lead to huge loss.