12 gram of carbon reacted with oxygen to produce CO and CO2 at 25 degree and at constant pressure.75Kcal heat was liberated and no carbon reacted.calculate the mass of oxygen which reacted.delata Hf(CO)=-24Kcal/mol and deltaHf(C))=-24Kcal
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It looks like the heat of formation values given are probably not right.
2 C + O2 => 2 CO Let us say a fraction = 2x moles formed CO.
C + O2 => CO2 Then a fraction 1 - 2x moles formed CO2.
We are initially given 1 mole (12 gms) of Carbon. So 2x moles of C and x moles of O2 combine to get 2x moles of CO.
(1-2x) moles of C combines with 1-2x moles of O2 to give (1-2x) moles of CO2.
Total enthalpy change from both reactions
= 2x * Hf(CO) + (1-2x) * Hf(CO2) - (x+1-2x) * Hf(O2) - (2x+1-2x) * Hf(C)
= - 75 Kcal = - 75 * 4.18 KJ
2x * (-110.5) kJ + (1-2x) * (-393.5) KJ - (1-x) * (0 ) KJ - (+1.88 ) KJ = - 75 * 4.18 KJ
x = 0.138
Total moles of oxygen reacted = 1 -x = 0.862
Mass of oxygen reacted = 0.862 * 32 = 27.584 gm
2 C + O2 => 2 CO Let us say a fraction = 2x moles formed CO.
C + O2 => CO2 Then a fraction 1 - 2x moles formed CO2.
We are initially given 1 mole (12 gms) of Carbon. So 2x moles of C and x moles of O2 combine to get 2x moles of CO.
(1-2x) moles of C combines with 1-2x moles of O2 to give (1-2x) moles of CO2.
Total enthalpy change from both reactions
= 2x * Hf(CO) + (1-2x) * Hf(CO2) - (x+1-2x) * Hf(O2) - (2x+1-2x) * Hf(C)
= - 75 Kcal = - 75 * 4.18 KJ
2x * (-110.5) kJ + (1-2x) * (-393.5) KJ - (1-x) * (0 ) KJ - (+1.88 ) KJ = - 75 * 4.18 KJ
x = 0.138
Total moles of oxygen reacted = 1 -x = 0.862
Mass of oxygen reacted = 0.862 * 32 = 27.584 gm
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