Answer:
2 C₇H₅N₃O₆ + 10.5 O₂ → 14 CO₂ + 5 H₂O + 3 N₂
73.96 g
Explanation:
Trinitrotoluene (TNT), C₇H₅N₃O₆, combines explosively with O₂ to produce CO₂, H₂O, and N₂. The balanced equation is:
2 C₇H₅N₃O₆ + 10.5 O₂ → 14 CO₂ + 5 H₂O + 3 N₂
The molar mass of C₇H₅N₃O₆ is 227.13 g/mol and there are 2 moles in the balanced equation. Then, 2 × 227.13 g = 454.26 g participate in the reaction.
The molar mass of O₂ is 31.998 g/mol and there are 10.5 moles in the balanced equation. Then, 10.5 × 31.998 g = 335.98 g participate in the reaction.
The mass ratio of C₇H₅N₃O₆ to O₂ is 454.26 g:335.98 g. The mass of O₂ that reacts with 100.0 g of TNT is:
100.0 g C₇H₅N₃O₆ × (335.98 g O₂/454.26 g C₇H₅N₃O₆) = 73.96 g O₂
D, 2Cu + O2 → 2CuO. A is wrong because oxygen is a diatomic element, meaning it always has to come in the form of O2 in the case of gas. B is wrong because the equation isn't balanced correctly; there's two oxygens on the reactants side, while only one oxygen on the products side. C is wrong because it's saying you're STARTING OUT with CuO already: that doesn't correspond with the word problem. Thus leaves D, where the equation is balanced correctly, has the diatomic oxygen, and ends with CuO.
