Chemistry enthalpy

Question

How many moles of isooctane must be burned to produce 100 kJ of heat under standard state conditions?

Answer 1

∆H = -5461 kJ/mole (looked up on the internet; your value may be slightly different)

100 kJ x 1 mole / 5461 kJ = 0.0183 moles iso-octane needed = 0.02 moles (1 sig. fig.)