Wat is the Molecular formula for Adenine (Empirical Formula: CHN) given that the Molecular weight is 135g?..... Can you show me how you worked through the problem to get the answer?

Question

Wat is the Molecular formula for Adenine (Empirical Formula: CHN)  given that the Molecular weight is 135g?..... Can you show me how you worked through the problem to get the answer?

4n1m0s1ty · Answer

I don't know if there is a better way to solve this, but the only way that I can see to get the correct answer is to guess the solution until you find a correct mw. You basically just keep multiplying the empirical formula until you get the molecular formula that matches. So start with CHN, then C2H2N2, then C3H3N3, and so on. Eventually, you will get to:
 $$C_{5} H_{5} N_{5}$$
MW of C is ~12 g
MW of H is ~1 g
MW of N is ~14 g

12 * 5 + 1 * 5 + 14 * 5 = 135 g

Which matches, so thats your answer. If you look at the structure for adenine you can see that this formula is true.

anonymous · Answer

Thank you that helped

anonymous · Answer

You dont ever need to simplify the molecular formula do u ?

4n1m0s1ty · Answer

Be careful, molecular formulas can never be simplified. If you simplified it, that would be the empirical formula.

4n1m0s1ty · Answer

Adding/subtracting atoms from a molecule makes it a different molecule

anonymous · Answer

ok thnks

anonymous · Answer

!