Question

Chem question!! With reference to the "Chemistry at Work" box on explosives, use bond enthalpies to estimate the enthalpy change for the explosion of 1.00 g of nitroglycerin.
I found that the answer is 7.85 KJ, but how?

Answer 1

The mass of nitroglycerin is 1 g,

Molar mass of nitroglycerin is 227 g/mol

The number of moles = moles/molar mass

= 1 g / 227 g/mol

= 0.004405 mol

The equation for the bond enthalpy of the reaction is shown below, thus, the total enthalpy change in the reaction is as follows:

ΔHreaction = Number of moles (∑ΔHbond break - ∑ΔH bond forms)

= 0.004405 mol × -3564.5 kJ/mol

= -7.85 kJ