Question

method to measure soluble organic carbon in seawater includes oxidation of the organic materials to CO2 with K2S2O8, followed by gravimetric determination of the CO2 trapped by a column of Ascarite. A water sample weighing 6.234 g produced 2.378 mg of CO2 (FM 44.009). Calculate the ppm carbon in the seawater.

Answer 1

Answer:

The ppm carbon in the seawater is 104.01.

Explanation:

Mass of seawater = 6.234 g

Mass of carbon dioxide gas  produced = 2.378 mg = 0.002378 g

1 mg = 0.001 g

Moles of carbon dioxide gas = $\frac{0.002378 g}{44.009 g/mol}=5.4034\times 10^{-5} mol$

1 mol of carbon dioxde gas has 1 mole pf carbon atoms,then $5.4034\times 10^{-5} mol$ will have ;

$1\times 5.4034\times 10^{-5} mol=5.4034\times 10^{-5} mol$ of carbon

Mass of $5.4034\times 10^{-5} mol$ of carbon ;

$12 g/mol\times 5.4034\times 10^{-5} mol=0.0006484 g$

To calculate the ppm of oxygen in sea water, we use the equation:

$\text{ppm}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^6$

(Both the masses are in grams)

$=\frac{0.0006484 g}{ 6.234 g}\times 10^6=104.01 ppm$

The ppm carbon in the seawater is 104.01.