How Do You Calculate the Percent Composition of Dopamine?

AI Thread Summary
To calculate the percent composition of dopamine (C8H11O2N), the total molecular weight is determined to be 153 amu. The individual contributions are calculated as follows: carbon (C) contributes 64.0 amu, hydrogen (H) contributes 11.0 amu, oxygen (O) contributes 32.0 amu, and nitrogen (N) contributes 14.01 amu. The percent compositions are approximately 41.8% for carbon, 7.2% for hydrogen, 20.9% for oxygen, and 9.2% for nitrogen. The initial calculations presented were incorrect, as the total molecular weight was miscalculated.
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% (by mass) composition

Homework Statement


Dopamine, C8 H11 O2 N is a neutroransmitter. Determine the percent (by mass) composition of each of the elements in dopamite.

Homework Equations


The Attempt at a Solution


8C atoms= 12 (12.0) = 44.0amu
11H atoms = 11 (1.0) = 11.0 amu
2O atoms = 2 (16.00) = 32.0 amu
1N atoms = 1 (14.01) = 14.01 amu
total: 101.01 amu

%C (8)(12.0 amu)
______________ = 95.0%
101.01
%H (11)(1.0 amu)
_____________ = 10.8%
101.01

%O (2)(16.00)
_______________ = 31.6%
101.01

%N (1)(14.01)
___________ = 13.8%
101.01
please help/tell me if its correct or not.
 
Last edited:
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8*12 is not 44.

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As it were, your calculations indicate a higher mass than is possible.

C8 H11 O2 N

MW = 8*12 + 11 + 2*16 + 14 = 96 + 11 + 32 + 14 = 153
 
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