Chem help!!! Please?

Question

86

Serotonin is a compound that conducts nerve impulses in the brain. It contains 68.2 mass percent C, 6.86 mass percent H, 15.9 mass percent N, and 9.08 mass percent ). Its molar mass is 176 g/mol. Determine its molecular formula.

Please show all work and explain if u want

I have listed this question several times to get in noticed so please just answer one of them

thanks for ur help and yes i tried on my own first and got some where but i know its all wrong.

Answer 1

% mass is grams:

68.2 grams C

6.86  grams H

15.9  grams N

9.08  grams O

find moles, using molar masses:

68.2 grams C @ 12.0 g/mol = 5.68 moles C

6.86  grams H @ 1.01 g/mol = 6.79 moles H

15.9  grams N @ 14.0 g/mol = 1.14 moles N

9.08 grams O @ 16.0 g/mol = 0.568 moles O

ratio the moles:

5.68 moles C / 0.568 moles = 10 mole C

6.79 moles H  / 0.568 moles = 12 mole H

1.14 moles N / 0.568 moles = 2 mole N

0.0568 moles O / 0.568 moles = 1 mole O

your empirical formula is C10 H12 N2 O

since this has a formula mass of 176 g/mol

which matches your molar mass,...

your answer is : C10 H12 N2 O  is your molecular formula

9.08  grams O