A sample of 1.0g of solid `Fe_(2)O_(3) of 80%` purity is dissolved in a moderately concentrated HCl solution which is reduced by zinc dust. The resulting solution required 16.7mL of a 0.1M solution of the oxidant. Calculate the number of electrons taken up by the oxidant.

Options

A. 5
B. 2
C. 4
D. 6

Answer

D

Explanation

Weight of pure `Fe_(2)O_(3) = (1 xx 80)/(100) =0.8g`
`Fe_(2)O_(3) +6HCI rarr 2FeCl_(3) +3H_(2)O`
`2FeCl_(3) +H_(2) overset("Zn dust")rarr 2FeCl_(2) +2HCl`
`Fe^(++) +` Oxidant `rarr Fe^(+++) +` reductant t
Eq. wt of `Fe_(2)O_(3) = ("Mole. wt")/(2) = (160)/(2) = 80g`
meq of `Fe_(2)O_(3) =` meq of oxidant
`(0.8)/(80) xx 10^(3) = 16.7 xx 0.1(x)`
`:. x = 6`