Q9E

Question

What is the mass of fish, in kilograms, that one would have to consume to obtain a fatal dose of mercury, if the fish contains \({\bf{30}}\)parts per million of mercury by weight? (Assume that all the mercury from the fish ends up as Mercury (II) chloride in the body and that a fatal dose is \({\bf{0}}.{\bf{20}}{\rm{ }}{\bf{g}}\) of\({\bf{HgC}}{{\bf{l}}_2}\).) How many pounds of fish is this?

Step-by-Step Solution

Verified
Answer

The mass of fish,\(m(fish)\) is 6.67 kg.

1Step 1: Mass

Mass represents the value of any matter contained in an object. It is expressed in kilograms (kg). It does not have any dimension.

2Step 2: Determine the mass of fish
  • \(30{\rm{ppm}} = 30{\rm{mg}}/{\rm{kg}}\) (Ppm is usually \({\rm{mg}}/{\rm{L}}\)but since here it is written "per weight", we are using \({\rm{mg}}/{\rm{kg}}\)which is also \({10^6}\)larger unit).
  • To calculate the amount of fish, divide the lethal dose by the concentration of mercury in the given amount of fish.

 

 

The calculation is as follows:

 

\({\bf{m(fish) = }}\frac{ { {\bf{m( lethaldose )}}}}{{{\bf{m( concentration )}}}}\)

 

\(m(fish) = \frac{{0.20g}}{{30 \times {{10}^{ - 3}}g/kg}}\)

 

\(m(fish) = 6.67kg\)