The combustion of one mole of benzene, C₆H₆, in oxygen liberates 3268 kJ of heat. The products of the reaction are carbon dioxide and water. How much heat is given off when 183 g of oxygen are reacted with excess benzene A) 2290 kJ B) 2490 kJ C) 2690 kJ D) 2890 kJ E) None of the above

Question

Quizplus · Accepted Answer

The balanced chemical equation for the combustion of benzene in oxygen is:

C6H6 + 15O2 → 6CO2 + 3H2O

For the combustion of one mole of benzene, 3268 kJ of heat is liberated. Therefore, the heat liberated for the combustion of 1 mole of benzene in oxygen is 3268 kJ.

The molecular weight of benzene is 78 g/mol. Therefore, 183 g of oxygen is equivalent to (183/32) moles of oxygen.

One mole of benzene requires 15 moles of oxygen to burn completely. Therefore, (183/32) moles of oxygen would be enough to burn (183/32)*(1/15) moles of benzene.

Since heat liberated is directly proportional to the number of moles of benzene burned, the heat liberated when (183/32)*(1/15) moles of benzene are burned in oxygen is equal to:

Heat liberated = 3268 kJ/mol * (183/32)*(1/15) mol = 2490 kJ

Therefore, the answer is B) 2490 kJ.

The Combustion of One Mole of Benzene, C6H6, in Oxygen

The Combustion of One Mole of Benzene, C₆H₆, in Oxygen