Question

NEED HELP!
C=46.67%, H=4.48%, N=31.10%, O=17.76%.
The molecular weight is 180.16g/mol.

Answer 1

`C_7H_8N_4O_2`

Step-by-step explanation:

Hello!

In this case, since the determination of an empirical formula is covered by first computing the moles of each atom as shown below:

`n_C=(46.47g)/(12g/mol)=3.9mol\\\\ n_H=(4.48g)/(1g/mol) =4.5mol\\\\n_N=(31.10g)/(14g/mol) =2.2mol\\\\n_O=(17.76g)/(16g/mol) =1.1mol`

Now, we divide each moles by the fewest moles (those of oxygen), to obtain the subscripts in the empirical formula:

`C:(3.9)/(1.1)=3.5 \\\\H:(4.5)/(1.1)=4 \\\\N:(2.2)/(1.1) =2\\\\O:(1.1)/(1.1) =1`

Thus, the empirical formula, taken to the nearest whole subscript is:

`C_7H_8N_4O_2`

Whose molar mass is 180.16, therefore the empirical formula is the same to the molecular one.

Best regards!