Question

The change in internal energy for the combustion of 1.0 mol of octane at a pressure of 1.0 atm is -5084.1 kJ. You may want to reference (Pages 381 - 385) Section 9.6 while completing this problem.

Answer 1

This is an incomplete question, here is a complete question.

The change in internal energy for the combustion of 1.0 mol of octane at a pressure of 1.0 atm is -5084.1 kJ. You may want to reference (Pages 381 - 385) Section 9.6 while completing this problem. If the change in enthalpy is -5074.2 kJ, how much work is done during the combustion? Express the work in kilojoules to three significant figures.

Answer : The work done during the combustion is, 9.9 kJ

Explanation :

Formula used :

$\Delta H=\Delta E+w$

where,

w = work done = ?

$\Delta H$ = change in enthalpy  = -5074.2 kJ

$\Delta E$ = change in internal energy  = -5084.1 kJ

R = gas constant = 8.314 J/mol.K

Now put all the given values in the above formula, we get:

$-5074.2kJ=-5084.1kJ+w$

$w=9.9kJ$

Thus, the work done during the combustion is, 9.9 kJ