All you have to do is a simple division "parts over the whole"
12.3 grams H/ 110 grams compound x 100= 11.2%
Assuming we have 100 g of sample
30.45/MW of N 14g = 2.175
69.55/MW of O 16g = 4.34
4.34/2.185 = 2
for every 1 mole of N we have 2 moles of O
so the empirical formula would be NO2
without having the molecular weight of the entire molecule the molecular formula can not be determined with the information in your question
In chemistry, the molar mass of a chemical compound is defined as the mass of a sample of that compound divided by the amount of substance in that sample, measured in moles.
The first reaction is a synthesis reaction (A+B -> AB)
