Question

Calculate the mass percent composition of nitrogen in NH4OH.

Answer 1

Step-by-step explanation:

1st) It is necessary to calculate the molar mass of NH4OH:

- N atomic mass: 14 g/mol

- H atomic mass: 1.01 g/mol

- O atomic mass: 15.99 g/mol

We have to multiply the atomic mass of each element by its subscript in the NH4OH formula:

- N atomic mass x 1 = 14 g/mol

- H atomic mass x 5 = 5.05 g/mol (in this case the total number of H in the molecule is 5)

- O atomic mass x 1 = 15.99 g/mol

Now we have to add all:

NH4OH molar mass = 14 g/mol + 5.05 g/mol + 15.99 g/mol

NH4OH molar mass = 35.04 g/mol

2nd) Finally, we can calculate the mass percent of nitrogen in NH4OH, assuming that the molar mass of NH4OH (35.04g/mol) is the 100%. It is necessary to use the total amount of nitrogen in the NH4 molecule (14 g):

`\begin{gathered} 35.04g-100\% \\ 14g-x=(14g*100\%)/(35.04g) \\ x=39.9\% \end{gathered}`

So, the mass percent composition of nitrogen is 39.9%.