## Trending News

# A sample of a compound with nitrogen and hydrogen has 7.207g N and 1.037g H. Molar mass of compound is 32 g. What is its molecular formula?

I tried this and my answer was N4H8 but I was incorrect. Anyone know how to do this?

### 2 Answers

Relevance

- Bobby_ThinLv 72 months ago
moles of N in your sample = 7.207g / 14 g/mol = 0.515 moles

moles of H = 1.037g / 1.004 g/mol = 1.033 moles

molar ratio N:H = 0.514: 1.033 or 1:2

empirical formula is the molar ratio of the elements or NH2

empirical formula mass = 16 g (14+2)

molar mass is given as 32 g / mole so there are 2 empirical formula mass units / mol of your compound

so 2 * NH2 = N2H4 ..

- Login to reply the answers

- KennyBLv 72 months ago
N4H8 has a molar mass of 72 - your answer should be N2H4

- Roger the MoleLv 72 months agoReport
You are correct to point out that N2H4 does not meet the requirement in the question, but 72 is not the number. You seem to have counted the hydrogens twice.

- Login to reply the answers

Still have questions? Get your answers by asking now.