Answer to Question #146658 in General Chemistry for Anna

Question

Using the following thermochemical equation for the combustion of ethanol, calculate grams of ethanol (C6H6O) needed to produce 2900 kj of heat. The molar mass of ethanol is 46.07 g/mol
C2H6O (I) + 3 O2 (g) —-> 2 CO2 (g) 3 H2O (g) Change H rxn = -1368

Answer 1

One mole of ethanol releases 1368kJ of energy when combusted.To get the number of moles divide 2900kJ $\dfrac{2900}{1368}=2.1moles$

The molar mass of ethanol is 46.07g/mol.

Mass of ethanol is $2.1 moles*46.07=96.68g$