Respuesta :
Answer:
a) 213.3 mg/L
b) 62.61 mg/L
c) 0.0225 mg/L
Explanation:
Theoretical oxygen demand (ThOD)is essentially the amount of oxygen required for the complete degradation of a given compound into the final oxidized products
a) Given:
Concentration of acetic acid,[tex][CH3COOH][/tex] = 200 mg/L
[tex]CH3COOH + 2O2 \rightarrow 2CO2 + 2H2O[/tex]
[tex]ThOD = \frac{mass\ O2}{mass\ CH3COOH} * conc. CH3COOH[/tex]
Based on the reaction stoichiometry:
mass of [tex]CH3COOH[/tex] = 60 g
mass of [tex]O2[/tex]= 2(32) = 64 g
[tex]ThOD = \frac{64 g}{60 g} * 200mg/L = 213.3 mg/L[/tex]
b) Given:
Concentration of ethanol, [tex][C2H5OH][/tex] = 30 mg/L
[tex]C2H5OH + 3O2 \rightarrow 2CO2 + 3H2O[/tex]
[tex]ThOD = \frac{mass\ O2}{mass\ C2H5OH} * conc. C2H5OH[/tex]
Based on the reaction stoichiometry:
mass of [tex]C2H5OH[/tex] = 46 g
mass of [tex]O2[/tex]= 3(32) = 96 g
[tex]ThOD = \frac{96 g}{46 g} * 30mg/L = 62.61 mg/L[/tex]
c) Given:
Concentration of sucrose, [tex][C12H22O11][/tex] = 50 mg/L
[tex]C12H22O11 + 12O2 \rightarrow 12CO2 + 11H2O[/tex]
[tex]ThOD = \frac{mass\ O2}{mass\ C22H22O11} * conc. C12H22O11[/tex]
Based on the reaction stoichiometry:
mass of [tex]C12H22O11[/tex] = 342 g
mass of [tex]O2[/tex]= 12(32) = 384 g
[tex]ThOD = \frac{384 g}{342 g} * 50mg/L = 0.0225 mg/L[/tex]
