Question

How many atoms of hydrogen are in 2.89 x 10^21 molecules of tryptophan (C11H12N2O2)?

Answer 1

1) Atoms to molecule ratio

1 molecule of C11H12N2O2: 12 atoms of H

2) Converting molecules of C11H12N2O2 to atoms of H.

`\text{atoms of H=2.89}\cdot10^(21)C_(11)H_(12)N_2O_2\cdot\frac{12\text{ atoms of H}}{1moleculeofC_(11)H_(12)N_2O_2}=3.468\cdot10^(21)atomsofH_{}`

There are 3.468*10^21 atoms of H.