Using the following thermochemical equation, determine the amount of heat produced from the combustion of 24.3 g benzene (c6h6). the molar mass of benzene is 78.11 g/mole. 2 c6h6(l) + 15 o2(g) → 12 co2(g) + 6 h2o(g) δh°rxn = -6278 kj

ΔH = -976.5 kJ

Explanation:

For the reaction given, there are 2 moles of benzene (C6H6). The heat of this reaction is -6278 kJ, which means that the combustion of 2 moles of benzene will lose 6278 kJ of heat. It is an exothermic reaction.

The value of ΔH, the enthalpy, is a way of measurement of the heat, and it depends on the quantity of the matter (number of moles).

So, 24.3 g of benzene has :

n = mass/ molar mass

n = 24.3/78.11

n = 0.311 moles

2 moles -6278 kJ

0.311 moles x

By a simple direct three rule:

2x = -1953.08

x = -976.5 kJ

the answer is na (sodium)