Question

What is the empirical formula of a compound that is 15.65% Carbon, 2.16% Hydrogen, 18.26% Nitrogen, and 63.10% Oxygen?

Answer 1

`\mathbf{ CH_2NO_3}`

Explanation:

Element %by
`(C)`
`(H)`
`(N)`
`(O)`

composition 15.56 2.16 18.26 63.16

mole ratio

`(\% \ by \ mass)/(atomic \ number )`
`(15.56)/(12)`
`(2.16)/(1)`
`(18.26)/(14)`
`(63.16)/(16)`

`= 1.297`
`2.16`
`1.304`
`3.948`

Divide by the

smallest value
`= (1.297)/(1.297)`
`= \frac{2.16 } {1.297}`
`= \frac{1.304} {1.297}`
`= \frac{3.948} {1.297}`

ratio
`1` :
`2` : 1 : 3

The empirical formula is =
`\mathbf{ CH_2NO_3}`