Answer:
2,2,4-trimethylpentane has the higher heat of combustion in kcal/mol.
Explanation:
Heat of combustion is defined as heat evolved on combustion of 1 mole of a substance.
2,2,4-trimethylpentane has the higher heat of combustion in kcal/mol.
Heat combustion of 2,2,4-trimethylpentane = (1304 kcal/mol) and
[tex]C_8H_{18}+\frac{25}{2}O_2\rightarrow 8CO_2+9H_2O,\Delta H=-1,304 kcal/mol[/tex]
1 mole of 2,2,4-trimethylpentane on combustion gives 8 mole sof carbon dioxide gas and 9 moles of water.
Heat combustion of ethanol = (327 kcal/mol)
[tex]C_2H_5OH+3O_2\rightarrow 2CO_2+3H_2O,\Delta H=-327kcal/mol[/tex]
1 mole of ethanol on combustion gives 2 moles of carbon dioxide gas and 3 mole of water.
Heat combustion of ethanol < Heat combustion of 2,2,4-trimethylpentane
