Formation Reaction Problems: No Idea how to solve it

[leftync1128]

Write formation reactions at 1 atmosphere pressure and 25°C for each of the following substnaces:
Mercury (I) chloride solid
Nitroethane (CH3CH2NO2) liquid

I have absolutely no idea how to do this. If anyone can help show or explain to me how to solve this, I'd appreciate it

 

[BlackHole213]

Are you sure it is 25 degrees C because the 1 atmosphere (101.325 kpa) is STP but the 25 degrees C is not at STP, but SATP.

If you know how to write normal formation reactions, write it that way. However, do not take my word for law. I'd suggest to ask you teacher if no one else on this forum answers this question.