Question

Reaction enthalpy for ethanol oxidation, C2H5OH+3O2 -> 2CO2 + 3H2O is 1257 kJ/mole. Energy content per mol fuel ______kJ Energy content per gram fuel = ____________ kJ Energy released per mol CO2 formed ________ kJ Energy released per mol O2 consumed= ______ kJ Moles of CO2 formed per 1000 kJ energy released ___________

Answer 1

Answer:

Energy content per mol fuel 1257 kJ.

Energy content per gram fuel = 27.33  kJ

Energy released per mol carbon dioxide gas formed is 628.5 kJ

Energy released per mol oxygen gas consumed= 419 kJ

Moles of carbon dioxide gas formed per 1000 kJ energy released is 1.591.

Explanation:

$C_2H_5OH+3O_2\rightarrow 2CO_2 + 3H_2O,\Delta H= 1257 kJ/mol$

1) Energy released per mole or fuel that is ethanol :

$1mol \times 1257 kJ/mol=1257 kJ$

2) Mass of 1 mole of ethanol = 46 g

46 grams of ethanol produces 1257 kJ of energy

Energy content per gram fuel :

$\frac{1257 kJ}{46 g}=27.33 kJ/g$

3) Energy released when 2 moles of carbon dioxide are formed = 1257 kJ

Energy released per mol of carbon dioxide formed:

$\frac{1}{2}\times 1257 kJ/mol=628.5 kJ/mol$

4) Energy released when 3 moles of oxygen gas are consumed = 1257 kJ

Energy released per mol of oxygen gas consumed:

$\frac{1}{3}\times 1257 kJ/mol=419 kJ/mol$

5) Energy released when 2 moles of carbon dioxide are formed = 1257 kJ

Moles of carbon dioxide gas formed per kilo Joule of energy:

$\frac{2}{1257} mol$

Moles of carbon dioxide gas formed when 1000 kJ of heat is released:

$\frac{2}{1257} \times 1000 mol=1.591 mol$