HELP!! When nitroglycerin (C3H5N3O9) explodes, it decomposes into the following gases: carbon dioxide, nitrogen, nitrogen monoxide, and water vapor. If 239g of nitroglycerin explodes, what volume of water vapor will be produced at 45.00 inHg and 2678C?

Idk the answer sorry

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.