`1.5gm` mixture of `SiO_(2)` and `Fe_(2)O_(3)` on very strong heating leave a residue weighting `1.46gm`. The reaction responsible for loss of weight is . `Fe_(2) O_(3) (s) rarr Fe_(3)O_(4) (s) + O_(2)(g)`
What is the percentage by mass of `Fe_(2)O_(3)` is original samle .

Options

A. `80%`
B. `20%`
C. `40%`
D. `60%`

Answer

A

Explanation

`3Fe_(2)O_(3)(s)rarr2Fe_(3)O_(4)(s)+(1)/(2)O_(2)(g)`
`(x)/(160)"moles" " "(1)/(6)xx(x)/(160)`
`(x)/(6xx160)xx32=0.04`
`x=1.2`
`%=(1.2)/(1.5)xx100 = 80`