Question

The most abundant element in seawater is chlorine. Seawater contains 19,000 mg of chlorine per liter. How do you calculate this as kilograms per cubic meter?

Answer 1

The concentration is `"19 kg/m"^3`.

Explanation:

Step 1. Convert milligrams to kilograms.

`"19 000" color(red)(cancel(color(black)("mg"))) × (1 color(red)(cancel(color(black)("g"))))/(1000 color(red)(cancel(color(black)("mg")))) × "1 kg"/(1000 color(red)(cancel(color(black)("g")))) = "0.019 kg"`

Step 2. Convert litres to cubic metres.

`1 color(red)(cancel(color(black)("L"))) × ("1 m"^3)/(1000 color(red)(cancel(color(black)("L")))) = "0.001 m"^3`

Step 3. Calculate the new concentration.

`"19 000 mg"/"1 L" = "0.019 kg"/("0.001 m"^3) = "19 kg/m"^3`