If the heat of combustion for a specific compound is -1430.0 kj/mol and its molar mass is 59.25 g/mol, how many grams of this compound must you burn to release 409.20 kj of heat?

To be able to answer this item, one needs to use the proper dimensional analysis such that we arrive to the same unit of measures as given in the item. If we let x be the amount, in grams, of the certain substance then, we may use the equation,

                  409.20 kJ = (x g)(1 mol/59.25 g)(1430 kJ/mol)

The value of x from the equation is 16.95 g.

16.95 g

Your question is not clear but if you can explain yourself i would be glad to .  just trying to : ))