Answer:
Answer is given below.
Explanation:
[tex]1mL=10^{-3}L[/tex]
So,[tex]1mL=10^{-3}L[/tex] seawater contains [tex]4.0\times 10^{-12}g[/tex] of gold
hence [tex]1.5\times 10^{21}L[/tex]seawater contains [tex]\frac{4.0\times 10^{-12}\times 1.5\times 10^{21}}{10^{-3}}g[/tex] gold or [tex]6.0\times 10^{12}g[/tex] gold
[tex]1g gold=48.64\$[/tex]
So, [tex]6.0\times 10^{12}g[/tex] gold = [tex]6.0\times 10^{12}\times 48.64\$ =2.9\times 10^{14}\$[/tex]
Seawater contains majorly different kinds of salts e.g. [tex]CaCl_{2},MgCl_{2}[/tex] 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.
