Hi,
I would like to see if I am going in the right direction with these types of problems:

Ammonia gas and 0.365 g of hydrogen chloride gas react to give 0.535 g of solid ammonium chloride. What is the mass of ammonia that reacted?

0.365 g HCl + mass of ammonia = 0.535 g of ammonia chloride
mass of ammonia = 0.535 g ammonia chloride – 0.365 h HCl
mass of ammonia = 0.17 g
Thanks for any help!

I think you need to take moles into account.