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.
Answer: 16.95 g