Verified answer

This is a lot easier then it seems.

Since its asking for just the reactant, you can ignore the whole left side. Now since its only asking for the reactant containing Nitrogen, you can ignore the NaHCO3 since it doesnt have nitrogen.

That leaves us with drawing the structure of NH4Cl.

This was a tough one for me to find, as I kept drawing Ammonia instead and couldnt figure out how to fit in the extra Hydrogen and Chlorine. Luckily, this Y!A answer explains it, its due to a hydrogen bond:

http://ca.answers.yahoo.com/question/index?qid=200...

Look in your chemistry book.